Documentation ICS-1000

ICS-1000 is a modular high performance data acquisition, archiving and processing system. It is intended for low frequency signals (less that 50Khz), but with many such signals (several hundreds) in parallel. The system is from the 90s nd was used e.g. in military research. End of lifetime for the product was 2010. ICS means Interactive Circuits and Systems Ltd., 5430 Canotek Rd., Gloucester, ON K1J 9G2, Canada.
ICS-1000 is also called ICS SYSTEM 1000. Main features of that system are:

  • Up to 500 Channels with Costs 500$/Channel (i.e. 250.000$ for 500 channels). My device has about 240 input channels and 64 output channels ….
  • VMEBus 64 Bit used („VME64x“)
  • VME64 Bus backplane with 20 slots
  • Rugged design for e.g. military use
  • LabvView + MATLAB interfaces for data analysis
  • VxWorks 5.1 as operating system

For the data processing cards in ICS-1000, software Library/Drivers exist for Solaris (1+2) and VxWorks. Complete source code of libs is available (see ICS-115 DAC Boad Datasheet page 11).I

As far as I understand, the case, power supply and VME64 backplane was taken as one part from the company „Carlo Gavazzi“. The CPU card is PowerPC-based from motorola, a 6 lines x 40 character display was taken from a company named „IEE“. Into this arrangement, ICS added it own set of data processing cards ICS 115 etc. Operating system is VxWorks 5.x.

The whole system seems to be out of the mid 90s.

Machine needs 430 Watts after being switched on 🙂

ICS Catalogue

Datasheets and manuals

ICS boards and MVME board

VxWorks and VME

PowerPC and used chips


WindRiver VxWorks 5.3.1, Serial-No #1783328

Additional Infos

Herkunft (Vermutung)

Dieses Gerät hat eintmals zwischen 100.000 und 250.000 Dollar gekostet. Nur Forschunginstitute, Universitäten, selbstforschende Konzerne und das Militär wird so ein Gerät kaufen und nutzen können.

An meinem Gerät sind Aufkleber entfernt, aber im Innern gibt es diese Aufkleber dann doch, und weisen auf die Bundeswehr als Vorbesitzer hin „(FWG/BW.“), konkret der „Forschungsanstalt der Bundeswehr für Wasserschall und Geophysik“ in Kiel. Der ebay-Verkäufer war übrigens aus Bremen. Mein Gerät besitzt auch einen Ausgang, der mit „Hydrophone“ bezeichnet ist, und Hydrophone werden für Sonarmessungen unter Wasser verwendet, was ein Hauptforschungsgebiet des FWGs in Kiel war und ist. Also würde ich sagen, das Teil kommt zu 99% Wahrscheinlichkeit vom FWG in Kiel.

Aus einer öffentlich zugänglichen eMail kann ich die Verwendung meines Geräts ableiten, es wurde als „Beamformer“ verwendet. Beamforming ist laut Wikipedia ein Verfahren zur Positionsbestimmung in (Schall)wellenfeldern. Dies ist ein Verfahren, mit dem „passiv“ Objekte geortet werden können, z.B. unter Wasser die Ortung fahrender (schallaussendender) U-Boote.

Allgemeine Artikel zu diesem Thema:


In my device, 13 cards are used.

Board name Description Number of cards
MVME2604 761 I/O 1x CPU PowerPC. „Single Computer Board“ with 32MB RAM, 333Mhz, SCSI, 100MBit LAN, Mouse & Keyboard connector, … 1
ICS 115-32 Delta sigma  DAC board, 32 bit – analog output, 50Khz Bandwidth 2
ICS 2200S  Front end DSP board, 640 MOPS 8
ICS 7220-SBFA Store of data / Interface to data recorders 1
ICS 7220-DxR Interface to Sony DIR100 Recorder (High Speed Data Recorder) 1
ICS 7220-ALU Data routing and formatting board 1

Storage media

  • SCSI harddisk NEC DSE 2100S 2GByte, SCSI2.
  • Matshushita Laser Disk Drive LKM F-934-1. Can read 1,44, 2,88 and 120MB floppys. The 120MB floppys are optical. Media name is „LS120“.


ABMVME2604-1331M REV B –> „333 Mhz PowerPC-CPU MPC604, 16-256MB ECC DRAM, 9MB Flash“ (see Installation Guide Page xvii)

My Models Ethernet MAC: 08003e2af939
Contains Firmware: PowerPC Bug (PPCBUG) in ROM

Usually, the CPU board is connected via a „transition module“ to peripherals (like SCSI disks, seriall/parallel interfaces, LAN). Motorola offers two different transition boards:

  • MVME712M
  • MVME761

They differ in the number and types of interfaces they offer.

ICS-1000 does not use such a prebuild transition module. The board’s connector with bus signls go to a small adapter card named „P2“. This PCB is build by ICS (Note: Motorola also offers a P2 board between CPU and transition module). The P2 module may only add SCSI termination and offers another 80-pin(?) connector that is routed via cable to another small PCB made by ICS. This second board offers 2x serial, 1x SCSI and 1x LAN connectors. The SCSI connector is routed to Harddisk and Floppy drive. One serial connector is routed to  SubD9 connector at the back of the device, the other one goes to the PEP VFD display via a null modem adapter. So the second board seems the ICS replacement for the Motorola transition board.

MVME177 CPU Board

This is another CPU board I own, so here is the information too. This board is not part of ICS1000.

NVRAM backup battery

The NVRAM backup battery was dead on my CPU board.
Type: 4T28-BR12SH1 – TIMEKEEPER SNAPHAT, XTal 32Khz + Battery 2,8V, 48mAh.

I found such a battery for ~4 euro in ebay and replaced the dead one.

Power supply, case VMEBus backplane

Inside the case there is a plate „MUPAC a Carlo Gavazzi Group Corporation. Model 5107WLF20TK-100 .“

I assume the number refers to the complete housing including backplane, case, power supply.

Carlo Gavazzi is a company that builds VME solutions, cases etc. Todays model numbers 5127… are cases from Carlo Gavazzi MUPAC with 20 lots. Carlo Gavazzi also produces backplane PCBs.

The power supply is a 1000 Watts one (no joke) with 5/12 volts.

Information on ICS-1000 and its components

(text below taken from and from old ICS website via Internet Wayback machine.

SYSTEM-1000: Fully Integrated Data Acquisition Solution

The SYSTEM-1000 base system can hold up to 20 VME 64x boards. ( The SYSTEM-1000ES is an extension product that includes embedded storage. It includes 12 VME 64x slots and 144 Gbytes of RAID storage. The RAID storage supports sustained data transfer rates of over 90 MBytes/s.)

The SYSTEM-1000/1000ES system is typically controlled from a PC via Ethernet. Extensive LabVIEW software is included for the PC for analysis and display. Options are also offered for high-speed data delivery to PC via FPDP.

The SYSTEM-1000 is particularly well suited for implementing any one or a combination of the following:

  • Simultaneous acquisition of a large number of analog channels;
  • Real-Time data recording/playback;
  • FibreChannel transmission of high-speed sensor data;
  • Simultaneous analog output of a large number of channels;
  • Front-end signal processing, such as FIR filtering, demodulation, beamforming, FFT, etc. and;
  • General sonar/radar receive, transmit and Sim/Stim processing.

Each system is packaged in a standard 19″ rack-mountable fan-cooled enclosure, which houses up to twenty (20) VMEbus boards (12 for SYSTEM-1000ES) along with an integrated dual-voltage 1000 W power supply. A powerful embedded processor running the VxWorks real-time operating system handles the control of each system. All of the software required to configure and control the SYSTEM-1000 is stored on an internal hard drive and is automatically loaded in to the memory of the embedded processor upon power up.

  •     An elegant 19″ rack-mountable enclosure (12″ high);
  •     Up to 20 slot VMEbus backplane;
  •     144 GB RAID storage (SYSTEM-1000ES);
  •     Over 90 Mbytes/s sustained data recording speed;
  •     A 1000 Watt power supply;
  •     Front Panel Touch-Screen Display;
  •     Floppy and hard drives;
  •     All system software;
  •     Host-independent graphical user interface (GUI) for control; and
  •     Easily upgradeable to adopt to future needs.

The SYSTEM-1000 is particulary well suited for implementing any one or a combination of the following:

  •     Simultaneous acquistion of a large number of analog channels;
  •     Real-Time data recording/playback;
  •     FibreChannel transmission of high-speed sensor data;
  •     Simultaneous analog output of a large number of channels;
  •     Front-end signal processing, such as FIR filtering, demodulation, beamforming, FFT, etc; and
  •     General sonar/radar receive, transmit and Sim/Stim processing.

ICS-115A 32-Channel 100Khz/Channel Delt-Sigma DAC boad

The ICS-115A is a 32-channel VMEbus DAC board that offers true 16-bit precision and update rates of up to 100 kHz/channel. The use of delta-sigma DACs offers a high degree of precision and digital interpolation, which moves the aliased image away from the signal band. This signigicantly relaxes post-filtering requirements. The ICS-115A provides differential outputs with high current drivers to directly drive large capacitive loads, and a 2-pole reconstruction filter for each DAC output is provided for each channel.

The ICS-115A board is ideal for sonar transmit, real-time simulation and digital audio applicatons. The ICS-115 is a slower speed version of the ICS-115A board that can operate at up to 50 kHz/channel update rate.

This product was discontinued on 01/18/2010.

ICS-115-yy      VMEbus DAC board. Standard 50 kHz version is supplied with 35 kHz reconstruction filter. Consult the factory for other filter options.
yy: number of channels (8, 16 or 32)
ICS-115A-yy     VMEbus DAC board. 100 kHz version supplied with 65 kHz filter.
yy: number of channels (8, 16 or 32)
DRV-115-VXW     Software device driver for VxWorks operating system.
DRV-115-SSS     Software device driver for Solaris operating system.

ICS-2200 Multi-Channel Time-Domain DSP Board

The ICS-2200 board is a Sharp LHBDSP9124 based DSP board that has been designed to solve compute-intensive front-end DSP problems with a sustained computing power of up to 640 MOPs in one VMEbus slot.

Some features of this board are:

  • Multi-channel FIR filtering/decimation;
  • Complex demodulation;
  • Replica correlation;
  • Real/complex beamforming;
  • Inverse beamforming, etc.

The ICS-2200 board is available in single (ICS-2200B, which replaces ICS-2200S) and dual (ICS-2200D) versions. The latter includes a second DSP device on a daughter card. The SHARP DSP chip offers 24-bit data, 24-bit coefficients and 60-bit accumulation. The board includes four specially designed hardware sequencers that control the operation of the board and manage the data flow. The I/O memories are dual-banked to allow apeturing or arbitrary selection of channel data for processing. The coefficient memories are also dual-banked to allow parameter updates without interrupting processing.

No. of Input Channels (NI):    Lesser of 8192 and (16384/ND)
No. of Outputs (NO):    Lesser of 8192 and (32768/NI-1)
Number of Coefficients (NT):    4 to 8192 (even numbers only)
Decimation (ND):        1 to 255
Delay for Beamforming and Inverse Beamforming (NDEL):   Lesser of 4096 and (1048576/NI)
Interpolation Resolution (Upsampling Ratio):    Over 1000 : 1 (Typical)
Coefficient Memory Size:        2 x 16 K x 24 (Dual port)
I/O Memory Size:        4 x 16 K x 32
History Data Memory Size:       2 x 512 K x 24
VMEbus Interface:       A32/24/16, D32 vectored interrupts
VSBbus Interface:       A32/D32 Polled interrupts
FPDP Interface:         2 reconfigureable FPDPs (80 MBytes/s)
Power:  3 A @ 5 V for ICS-2200B
6 A @ 5 V for ICS-2200D
Throughput Rate (Fs):   80 MHz / (NO x NT x NIA + NI + 96)
[For beamforming, NIA is not equal to NI when the number of inputs being processed is different from the total number of inputs, i.e., multiple aperture beamforming.]
80 MHz / (NO x NT x NI x 96)[For filtering]
{Specifications are subject to change without notice}

ICS-2200B       VMEbus DSP board with a single SHARP device
ICS-2200D       VMEbus DSP board with two SHARP devices
DRV-2200-VXW    Software device driver for VxWorks operating system
ASW-2200        Application software for the ICS-2200

ICS 7220 SBFA and DxR

FPDP Interface and Special Function Board
The ICS-7220 is a 6U VMEbus board that is designed to simplify interfacing to external equipment. In order to reduce the time and cost of developing special interfaces, the ICS-7220 board includes provisions for incorporating a daughter card.

Custom daughter boards for the ICS-7220 can also be developed by the user. ICS provides full technical assistance, free of charge, to any user wishing to develop a daughter card for the ICS-7220 board.

Standard daughter cards are now available for interfacing a wide variety of data recorders for data formatting of FPDP stream, and for generating random noise.

The ICS7220 DxR is an interface to a sony high speed data recorder.

ICS-7220 ALUB: FPDP Data Routing and Formatting Board

The ICS-7220 ALUB daughter card includes two input FPDP ports and one output FPDP port. Each input path includes a dual-port memory and a barrel shifter. A sequencer memory can select which data words (channels) to output from each dual-port in an arbitrary fashion. The ALUB unit can add, subtract and selectively merge the two FPDP data streams with the Datum real-time clock data. The 64-bit Datum clock input is sampled at the input FPDP frame rate and it is divided into two 32-bit words for merging with the input data. Note that while the data source for the primary input path is FPDP, the data source for the secondary input path can be either FPDP (daughter board) or VME64/VSB (mother board). The output from the ALUB is available via the FPDP at the input frame rate (either Main or Aux. FPDP). If the Aux. FPDP input is at a decimated frame rate, the output frame rate must be at the Main FPDP input frame rate. The ICS-7220-ALUB board can select any data word (channel data) from the primary, secondary and output data path for storage into the mother board’s swing buffer memories for VMEbus/VSB access. The ICS-7220 board also includes a 16-bit D/A converter for analog conversion of any selected output channel.

  •     Arbitrarily select data words from either inputs for FPDP output;
  •     Merge two input FPDP data streams;
  •     Merge Datum real-time clock data with the FPDP inputs;
  •     Merge or add VME64/VSB data with the main FPDP input;
  •     Select any channel (or data word) from each input for VME64 access;
  •     Select any FPDP output data word for D/A output; and
  •     Software device drivers for VxWorks.

ICS-7220-ALUB   General purpose interface motherboard.
DRV-7220-ALUB-VXW       Software device driver for VxWorks operating system.

Front Display

A „Vacuum Fluoreszent Display“, green, 6×40 chars. Model: PEP 04226-01
Out of the series „PEP Touch Screen Interface Display“ from IEE.  (

„The UL-recognized IEE Peripheral Entry Panel (PEP) is an interactive terminal assembly integrating a 6-line by 40-character VFD with an infrared switch matrix. Interaction with the host system occurs when the operator reads displayed messages and responds by finger contact with a touch sensitive switch location on the screen. Since the switch matrix uses optical technology, no annoying grids are present to degrade the appearance of the display.

  •     Bright, Easy to Read 6-line by 40-character VFD
  •     Infrared Touch Screen Immune to Ambient Light
  •     Single Piece, Drip-proof, Polycarbonate Bezel
  •     32 Kilobytes of Battery-backed RAM for Message Storage
  •     EIA-232 and EIA-422 Serial Interfaces at 1200 or 9600 Baud
  •     Single +5 VDC Power Supply
  •     Extended -40°C to +85°C Operating Temperature Range Available“



Front of  the device, switched on

„Breakout board“, 2 x serial connectors

„Breakout board“, SCSI connector

Harddisk and floppy drive


Display attached to a PC and some data was enetered via PCs keyboard – the display works…

Back of display

Display: Note jumpers at bottom of image

Display: power supply connector

Laser Disk Drive

MVME2604 761 I/O CPU Board

Board LEDs after switched on

On top of the main board, there is a daughter „mezzanine“ board carrying additional RAM and ROMs.
My daughter board adds another 16MB to the 16MB that are alredy on the main board. Furthermore, it adds 8MB ROM.

Bottom side.

Here, the NVRAM backup battery can be seen

The RAM/ROM mezzanine card

CPU= CPU Clock
PCI=PCI Bus Activity
FUS=FUSE ok/defect
SYS = Board is running as VME Bus Controller yes/no

No PCI Mezzanine card installed here

These our big chips are the interface devices for SCI, Network, serial, VMEBus etc.

ICS 115-32 DAC Output Board

VME64 Backplane

P2 Adapter


The ICS-2200 board is dominated by a big Butterfly DSP BDSP9124, a chip designed by Sharp/Butterfly. Around that chip, 9 other gold-plated chips are arranged. Moreobver there are 4 big Lattice FPGAs and one other big gold-plated chip on the board. 6 SRAM chips can also be seen.

Gold-plated chips:
2x dt7006 S25XL Y 9505S with sticker 7M1002 S35G 9529M
7x dt7099 S25XL Y 9444S with sticker 7M1024 S25G 9517AA

Lattice FPGAs
4x ispLSI 1048-80Q
where 95xx und 94xx are datecodes  (1994 und 1995 er Chips)

SEC KM684002J-20, this is 512Kx8 bit SRAM, this means the board has 3MB RAM.

At the front of the board, three connectors are located. P3, P4, P5.

ICS-7220 ALU


ICS-7220 DxR


Attempt to revive the ICS-1000


Die CPU-Karte muß immer im ersten Slot stecken. Von dort bekommt sie Strom etc. Mit dem Backplane ist die Karte über zwei Stecker verbunden, Einer der beiden Stecker trägt alle Signale, die nach draussen gehen. Diese werden über einen Adapter („P2“) auf ein  „Transition Board“ geroutet. Dieses  bildet die Bus-Signale auf Stecker ab für Seriell, Parallel, SCSI, LAN, …

Nach dem Einschalten des Geräts blinkt ein Cursor („_“), sonst passiert nichts. Wird der RESET-Button am CPU-Board gedrückt, kommt pro Drücken ein „#“ Zeichen auf den Bildschirm. Sonst kommt nichts und auch Eingabeversuche am Touchpanel haben keinen Effekt. Das CPU-Board hat bis zu 4 serielle Anschlüße, der erste ist die Systemkonsole, ich vermute dass das VFD nicht an der Console angeschlossen ist, sondern m rückseitigen Terminal-Anschluß,

Es wird übrigens auch nicht versucht von der HD zu booten. Auch die Floppy leuchtet nicht kurz auf. Die HD initialisiert sich (hört man), dann passiert nichts mehr.

Check with PEP Display: it is ok, RS232 parameters are 9800 8N1. Note that the PEP is connected to its serial connector via a Nullmodem adapter.

After attaching the PC with a Nullmodem-Adapter to the „Terminal-Connector“ at the back of the device, I can read the start of the boot process!

It says that it cannot access a boot device and goes to a vxVorks boot prompt. Checking the Internet regarding vxWorks booting, I issued the command „c“ and „p“ to get the current parameters set.

[VxWorks Boot]: c ‚.‘ = clear field; ‚-‚ = go to previous field; ^D = quit boot device : ATAGTDPPQ?T??G????&0 processor number : 0 host name : file name : inet on ethernet (e) : inet on backplane (b): host inet (h) : gateway inet (g) : user (u) : ftp password (pw) (blank = use rsh): flags (f) : 0x0 target name (tn) : startup script (s) : other (o) : [VxWorks Boot]: [VxWorks Boot]: ? ? – print this list @ – boot (load and go) p – print boot params c – change boot params l – load boot file g adrs – go to adrs d adrs[,n] – display memory m adrs – modify memory f adrs, nbytes, value – fill memory t adrs, adrs, nbytes – copy memory e – print fatal exception n netif – print network interface device address $dev(0,procnum)host:/file h=# e=# b=# g=# u=usr [pw=passwd] f=# tn=targetname s=script o=other boot device: scsi=id,lun file name: /sd0/vxWorks Boot flags: 0x02 – load local system symbols 0x04 – don’t autoboot 0x08 – quick autoboot (no countdown) 0x20 – disable login security 0x40 – use bootp to get boot parameters 0x80 – use tftp to get boot image 0x100 – use proxy arp available boot devices: dc bp sm scsi

Because the NVRAM buffer battery is defect, the data in NVRAM is nonsense and must be entered manually. But what values are correct?

Boot devices:

dc = Ethernet scsi : SCSI of course bp: ??? (backplane?) sm: ??? (floppy?)

After tring around, I found that the boot device must be named


Then the disk is accessed (I can hear the drive heads move :-). Now I tried to figure out the file name (name of kernel image, usually vxWorks). I got different error messages

error loading file: status = 0x610001. = file not found
tError loading file: errno = 0x37000b. -> LUN not present
Error loading file: errno = 0x370001. -> target not ready (disk gibts nicht)

Hm. After trying everything whih may be working, no process. So I need to read the harddisk content. This is not possible via boot prompt. In my linux PC, there is still a SCSI controller built in, it has a 50 pin iternal connector. So I took the harddrive SCSI cable from the transition module and connected it to my PCs SCSI adapter. First switching on the ICS-1000 gives power to the drive, and after initializing I switched on my PC. And tada, Linux detects the harddisk (by the way, the floppy drive WSC SLS-120 is also detected).

… [ 3.600580] ahc_pci:5:1:0: Host Adapter Bios disabled. Using default SCSI device parameters [ 18.603151] scsi10 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 7.0 [ 18.603153] <Adaptec 2902/04/10/15/20C/30C SCSI adapter> [ 18.603155] aic7850: Single Channel A, SCSI Id=7, 3/253 SCBs [ 18.603156] [ 18.732716] scsi 10:0:0:0: Direct-Access NEC DSE2100S 0306 PQ: 0 ANSI: 2 CCS [ 18.732729] scsi target10:0:0: Beginning Domain Validation [ 18.735414] scsi target10:0:0: FAST-10 SCSI 10.0 MB/s ST (100 ns, offset 15) [ 18.737189] scsi target10:0:0: Domain Validation skipping write tests [ 18.737192] scsi target10:0:0: Ending Domain Validation [ 18.739561] sd 10:0:0:0: [sdc] 4124736 512-byte logical blocks: (2.11 GB/1.96 GiB) [ 18.740015] sd 10:0:0:0: [sdc] Write Protect is off [ 18.740020] sd 10:0:0:0: [sdc] Mode Sense: 6f 00 00 08 [ 18.740994] sd 10:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn’t support DPO or FUA [ 18.751993] sdc: [ 18.754834] sd 10:0:0:0: [sdc] Attached SCSI disk [ 18.759352] scsi 10:0:1:0: Direct-Access WSC SLS-120 7.30 PQ: 0 ANSI: 2 [ 18.759364] scsi target10:0:1: Beginning Domain Validation [ 18.770478] scsi target10:0:1: FAST-10 SCSI 10.0 MB/s ST (100 ns, offset 15) [ 18.778124] scsi target10:0:1: Domain Validation skipping write tests [ 18.778127] scsi target10:0:1: Ending Domain Validation [ 18.787341] sd 10:0:1:0: [sdd] Attached SCSI removable disk [ 18.796494] scsi scan: INQUIRY result too short (5), using 36 [ 20.117413] hp_sw: device handler registered [ 20.119470] alua: device handler registered …
It is not possible to mount it, because it has an unknown filesystem on it. But I was able to make a bytecopy of the complete 2GB harddisk with the dd command:

socraggio:/home/dennis/ics1000 # dd if=/dev/sdc of=disk-image.img 4124736+0 Datensätze ein 4124736+0 Datensätze aus 2111864832 Bytes (2,1 GB) kopiert, 411,103 s, 5,1 MB/s

So the harddrive seems ok. I hope that the data on it was not deleted by someone and that the VxWorks installation is still on the harddisk…

Then I tried around with bvi (binary vi) and found that the drive has filesystem type „VXEXT1.0“. This is Wind River propietary, some special extension of old dos file system.
The data below must e.g. be a directory structure…

… 00040200 76 77 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 vw 00040218 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 00 00 FF FF 00 00 00 00 …….. 00040230 00 00 00 00 00 10 00 00 21 00 02 00 00 00 00 00 78 66 69 6C 65 73 20 20 ……..!…….xfiles 00040248 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 00040260 20 20 20 20 20 20 20 20 00 00 FF FF 00 00 00 00 00 00 00 00 00 10 00 00 ……………. 00040278 21 00 03 00 00 00 00 00 73 74 61 72 74 75 70 2E 65 78 65 20 20 20 20 20 !…….startup.exe 00040290 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 000402A8 00 00 FF FF 00 00 00 00 00 00 00 00 00 20 00 00 21 00 1E 00 FF C5 02 00 …………. ..!……. 000402C0 74 77 69 6E 36 61 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 twin6a 000402D8 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 00 00 FF FF 00 00 00 00 …….. 000402F0 00 00 00 00 00 10 00 00 21 00 21 00 00 00 00 00 73 79 73 65 78 74 2E 65 ……..!.!…..sysext.e 00040308 78 65 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 xe 00040320 20 20 20 20 20 20 20 20 00 00 FF FF 00 00 00 00 00 00 00 00 00 20 00 00 …………. .. 00040338 21 00 22 00 E3 F7 00 00 73 70 61 77 6E 2E 65 78 65 20 20 20 20 20 20 20 !.“…..spawn.exe 00040350 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 00040368 00 00 FF FF 00 00 00 00 00 00 00 00 00 20 00 00 21 00 23 00 3D 6C 00 00 …………. ..!.#.=l.. 00040380 6D 65 6E 75 64 72 69 76 2E 65 78 65 20 20 20 20 20 20 20 20 20 20 20 20 menudriv.exe 00040398 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 00 00 FF FF 00 00 00 00 …….. 000403B0 00 00 00 00 00 20 00 00 21 00 24 00 B5 77 00 00 66 6C 69 70 64 72 69 76 ….. ..!.$..w..flipdriv 000403C8 2E 65 78 65 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 .exe …
Just by looking at the byte strings I could not find out the name of the vxWorks kernel image. So I made a web search and found that there is a linux driver for the VXEXT file system.

This requires compiling a kernel module for this file system.

A short try with the current version of the VXEXT driver on OpenSuse 12.2 which uses Linux Kernel 3.4 fails. The VXEXT driver is a little bit outdated. I succeeded compiling it on a VM with OpenSuse 11.3 which uses Linux kernel 2.6.x . I needed to change in one file (misc.c) some 64-bit division (I was using a 32-bit Linux system which gave an unresolved symbol for the kernel module).  After that, It was a trivial task to mount the disk image created with the dd-command some days ago. I used the linux feature of mounting a file as a loopback device.

mount -t vtext -o loop disk-image.img /mnt2

So I was able to examine the content of the harddisk. I found that the vxWorks kernel „“ was located in a directory „vw“ on the disk. But this was not the complete solution… I found out that the argument „file name“ at the vxWorks boot prompt was not only the file name itself („/vw/“) but also included the boot device: „/scsi=0,0/vw/“ .

This leads me to the first sucessful boot:

boot device : scsi=0,00 processor number : 0 host name : ics file name : /vw/ /scsi=0,0/vw/ inet on ethernet (e) : inet on backplane (b): host inet (h) : gateway inet (g) : user (u) : ftp password (pw) (blank = use rsh): flags (f) : 0x0 target name (tn) : startup script (s) : startup.scr other (o) : [VxWorks Boot]: [VxWorks Boot]: @ boot device : scsi=0,0 unit number : 0 processor number : 0 host name : ics file name : /scsi=0,0/vw/ inet on ethernet (e) : gateway inet (g) : flags (f) : 0x0 startup script (s) : startup.scr 1510608 Starting at 0x100000… mounting tape drive scsiPhysDevCreate for tape device failed. Auto-configuring SCSI bus… ID LUN VendorID ProductID Rev. Type Blocks BlkSize pScsiPhysDev — — ——– —————- —- —- ——– ——- ———— 0 0 NEC DSE2100S 0306 0 4124736 512 0x017f7720 mounting SLS-120 floppy drive mounting hard drive Target Name: vxTarget User: target Attaching network interface lo0.. done. NFS client support not included. Adding 3588 symbols for standalone. shell is included CPU: Motorola MVME2600 – MPC 604e. Processor #0. Memory Size: 0x2000000. BSP version 1.1/4. WDB: Ready. Interactive Circuits And Systems Ltd SYSTEM-1000 Unable to open startup script startup.scr

I was not able to ping the machine after boot. I am still do not know what to enter for all these different IP adresses…

There is a startup-Script on the harddik, which is a text file. But I noted at the first boot, that the path would need also a leading „/scsi=0,0″…

There is some new information, e.g. the RAM size is 32MB (0x2000000) and the processor is a MPC604e. The vxWorks version is 5.3.1.

-> version VxWorks (for Motorola MVME2600 – MPC 604e) version 5.3.1. Kernel: WIND version 2.5. Made on Jul 24 2001, 13:45:51. Boot line: scsi=0,0(0,0)ics:/scsi=0,0/vw/ e= g= s=startup.scr value = 100 = 0x64 = ‚d‘

Finally the NVRAM buffer battery came in and i replaced it. As expected, the boot parameters are now persisted.

Next step was to setup the network.
After some reading I understand that the network hardware must be initialized during booting. To do that, you need to add the name of the network device to the „other“ parameter of the boot parameters. After trying around, I succeeded with the name „dc“.

The network device can be probed at the boot prompt with the netif ccommand.

n netif               – print network interface device address

[VxWorks Boot]: n dc
Address for device „dc0“ == 08:00:3e:2a:f9:38

The booting now includes also the network:

[VxWorks Boot]: @ boot device : scsi=0,0 unit number : 0 processor number : 0 host name : ics1 file name : /scsi=0,0/vw/ inet on ethernet (e) : host inet (h) : gateway inet (g) : flags (f) : 0x0 target name (tn) : ics startup script (s) : startup.scr other (o) : dc 1510608 Starting at 0x100000… mounting tape drive scsiPhysDevCreate for tape device failed. Auto-configuring SCSI bus… ID LUN VendorID ProductID Rev. Type Blocks BlkSize pScsiPhysDev — — ——– —————- —- —- ——– ——- ———— 0 0 NEC DSE2100S 0306 0 4124736 512 0x017f7720 mounting SLS-120 floppy drive mounting hard drive User: targetAttaching network interface dc0.. done. Attaching network interface lo0.. done. NFS client support not included. Adding 3588 symbols for standalone. shell is included CPU: Motorola MVME2600 – MPC 604e. Processor #0. Memory Size: 0x2000000. BSP version 1.1/4. WDB: Ready. Interactive Circuits And Systems Ltd SYSTEM-1000 Unable to open startup script startup.scr

Some more information can be gathered now from vxWorks

-> ifShow dc (unit number 0): Flags: (0x63) UP BROADCAST ARP RUNNING Type: ETHERNET_CSMACD Internet address: Broadcast address: Netmask 0xffffff00 Subnetmask 0xffffff00 Ethernet address is 08:00:3e:2a:f9:38 Metric is 0 Maximum Transfer Unit size is 1500 0 packets received; 0 packets sent 0 multicast packets received 0 multicast packets sent 0 input errors; 0 output errors 0 collisions; 0 dropped lo (unit number 0): Flags: (0x8069) UP LOOPBACK MULTICAST ARP RUNNING Type: SOFTWARE_LOOPBACK Internet address: Netmask 0xff000000 Subnetmask 0xff000000 Metric is 0 Maximum Transfer Unit size is 32768 12 packets received; 12 packets sent 0 multicast packets received 0 multicast packets sent 0 input errors; 0 output errors 0 collisions; 0 dropped value = 29 = 0x1d -> routeShow ROUTE NET TABLE destination gateway flags Refcnt Use Interface —————————————————————————- 3 1 15 dc0 —————————————————————————- ROUTE HOST TABLE destination gateway flags Refcnt Use Interface —————————————————————————- 5 1 0 lo0 —————————————————————————- value = 77 = 0x4d = ‚M‘

I found that CRTL-X immediately reboots the machine. No need to switch it off and on again and again.

Now I fumbled around with all these IP adresses and came up with the following parameters which are perfect:

boot device : scsi=0,0 unit number : 0 processor number : 0 host name : soc file name : /scsi=0,0/vw/ inet on ethernet (e) : flags (f) : 0x0 target name (tn) : ics startup script (s) : startup.scr other (o) : dc

Finally I also found out how to access the harddisk 🙂
cd „D:“
and the D needs to be capital letter…

The content of the startup script is

# startup script ld < startup.exe startUp routeAdd(„″,““) sp(flip)

This means that some callable functions are loaded („ld <…“) and one of those functions is called („startUp“). A static route is added and finally there is a task switch.

For some unknown reason, the startup script is found but not executed. If I execute the commands manually, everything is fine. This means that all the card drivers are loaded into memory and a controlling text application screen occurs on the built in display of the machine. There, clusters can be defined and controlled, machine parameters can be changed and data and configurations can be saved and loaded. Very nice.

I found that the machine runs a telnet and a ftp server which can be accessed anonymously and by user account.

To go on, I needed more knowhow regarding vxWorks, PowerPC execulatble and assembler and the oroiginal purpose of the device.

vXWorks random information

The way an executable is started in vxWorks is somehow funny. You can load a binary file (an exe) into memory. It is not immediatedly executed like when loading an executable in linux or windows, it just stays in memory., but all external accessible symbols (non-static C functions etc.) are accessible. There is no main symbol but all accessible symbols can be called just by entering their name at command line. So loading the „startup.exe“ loads all symbols (and code) for that binary, and you need to know the entry C function to call. For the example, this function is named „startUp“.  After being loaded into memory, a binary is named a „task“. Several commands can be executed on a task:

i – prints task info
td <task> – ends task (use task name or task id)

Add an environment variable:

putenv „DISPLAY=“

Display the environment: envShow

> envShow (global environment) 0: D:/xfiles 1: USE_LOCAL_FS 2: XKEYSYMDB=D:/xfiles/lib/xkeysym.db 3: DISPLAY= value = 28 = 0x1c

Further vxWorks commands:
adrSpaceShow(details 0, 1) – Show details of the Address Space, including physical address, User Region address and kernel virtual mapping.
envShow(taskId) – Show environment for a given task
iosDevShow – Show loaded I/O Devices
iosDrvShow – Show I/O Device Driver Function Table
iosFdShow – show open File Descriptors
memShow – show memory usage statistics
moduleShow – show downloaded modules
objShowAll – show the list of all the objects in the system (semaphores, tasks, msgQs, etc…)
objShow (objectId) – show detailed information about an object

Power PC Assembler, Binary files introspection


ICS 1000 additional information

Using Internet Archive‘ wayback machine, I was able to retrieve some more information about the ICS-1000. For example, I got  complete lit of all technical notes by ICS:

–> Tech Note #9 – ICS-2200: Time-Domain DSP Board
–> TTech Note #10 – ICS-2200B/D: Getting to Know The ICS-2200 Board
–> TTech Note #11 – ICS-7220:Versatile I/O Interface Board
Tech Note #14 – ICS-150 Super High-Speed Data Acquisition
–> TTech Note #15 – ICS-FPDP: A 160 MBytes/s Front-Panel Data Port
–> TTech Note #16 – ICS-115:Delta-Sigma DAC Board
–> Tech Note #20 – SYSTEM-1000 Providing System-Level Solutions to Real-Time Sensor Processing Applications
Tech Note #23 – ICS-151A 65 MHz Data Acquisition and Optional Signal Demodulation
Tech Note #24 – ICS-110BL 24-Bit Sigma-Delta ADC Board with Optional Signal Conditioning
Tech Note #25 – ICS-130 32-Channel, 16-Bit, High-Speed ADC Board
Tech Note #26: Digital IF Receive Processing
Tech Note #27 – ICS-550 65 MHz, ADC and Tuner PMC Modules
Tech Note #29 – ICS-121 32-Channel, 300 kHz, Signal Conditioning Board
Tech Note #32 – ICS-145 High-Speed, High-Precision, High-Density ADC Board
Tech Note #33 – ICS-650 2-Channel, 12-Bit, 65 MHz/Ch., Data Acquisition Board for PCI Bus
Tech Note #34 – ICS-131 32-Channel, 574 kHz Signal Conditioning Board
Tech Note #35 – ICS-141 32 Channel, 1 MHz Signal Conditioning Board
Tech Note #36 – ICS-152 A 65 MHz, 14-Bit ADC Board with Multiple Tuner Modules Options and FPDP and RACEway Interfaces
Tech Note #37 – ICS-610 A 32-Channel, 100 kHz/Ch., 24-Bit Data Acquisition Board for PCI Bus
Tech Note #38 – ICS-645 A 32-Channel, High-Speed, High-Precision PCI Bus ADC Board
Tech Note #39 – ICS-660B A 4-Channel, 14-Bit, 105 MHz/Ch., Analog Output Board for PCI Bus
Tech Note #40 – ICS-652 2-Channel, 14-Bit, 65 MHz/Ch., ADC Board
Tech Note #42 – ICS-660 Digital Modulation Using the ICS-660 and DC-60-M1 Modulator Module
Tech Note #43 – ICS-500 FPDP II PMC Buffer Module with PCI 64/66 Interface
Tech Note #44 – ICS-625B 32-Channel, 288 kHz/Ch., PCI DAC Board
Tech Note #45 – ICS-554 4-Channel, 14-Bit, 105 MHz PMC ADC Board with Down-Converters and Xilinx FPGA
Tech Note #46 – ICS-564 A 4-Channel, 14-Bit, 200 MHz DAC PMC Module with Integrated Digital Up-Converter and PCI 64/66 Interface
Tech Note #47: The DC-60-M2 Up-Converter Daughter Card for the ICS-660B DAC Board
Tech Note #48 – ICS-572A A 2 Channel ADC, 2 Channel DAC with Xilinx FPGA , SDRAM , QDR SRAM and PCI 64/66 Interface
Tech Note #49 – ICS-710 A 32-Channel, 216 kHz/Ch., 24-Bit 6U Compact PCI Data Acquisition Board
Tech Note #50 – ICS-725 A 32-Channel, 288 kHz/Ch., Compact PCI Bus DAC Board

Use the ICS-1000 system

After trying around, I was able to start the x windows programs in the directory „xfiles“.

putenv „DISPLAY=“ cd „D:“ ld <startup.exe cd „xfiles“ ld <xmain startGUI

Precodition on X Server:
YasT Security tab (preferred because this works) or below:
in /etc/sysconfig/displaymanager and don’t forget the „xhost +“. xhost+ must be installed from Yast since OpenSuse 13.2.
Check if XServer listens on port 6000: netstat -anp | grep 600

It gives some text output but more interesting, the x window output on my linux machine. The GUIs are from mid 1990s and do look poor, but they work. This seems to be an early OSF/Motif based GUI.

The ICS2200S in slot 5 and the DxR board failed the diagnostic test. But this may be related to incorrect jumpers or cabling.

Loading a cluster

View on a cluster definition

A „Cluster“ is obviously a configuration of several cards together with config data for each card.

Going On

To go on, the following steps are required

  • Get documentation, headers (and libraries?) for the different DSP boards inside the machine
  • Set up a cross-compile tool chain on OpeSuse. I read somewhere that gcc can compile code for the  MVME single board computer
  • Compile a simple appliction that uses DSP features, copy it to the machine and run it.

Get headers and Libraries

Libraries: Because there are no libraries in VxWorks, I need no libs. Everything is linked against the .o files and the .exe files loaded into memory of the target.

Headers: It was found that it is impossible today to get the headers. So I examined the exe-Files to see if I can recreate the headers from them. The exes have been compiled with debugging information, so all typedefs and enums were still in. Also, the original function prototypes from the c-files are inside the exes.

The GNU tool objdump is able to disassemble the exes. „objdump -g“ dumps out the debugger information. This includes the include-hierarchy, the typedefs/enums found and for c-files, the function definitions with line-number- linking to the original source files. I do not have the original source files, but what i get from objdump gives me the function prototypes and thats enough.

What is missing are:

  • defines (#define XYZ 13.2) are replaced by preprocessor, so c compiler does not see them. They can not be reproduced in this way.
  • The correlation (what typedef was in what header) is away. There is some kind of correlation, but this is not exact. For example: if stdio.h includes sys/blah.h I cannot decide if a typedef comes from stdio.h or from sys/blah.h. My approach is to put everything found that cannot be located exactly, into the first header file (here: stdio.h).
    This will lead to the situation that original source code may give erros, but no problem, I have no original source code at all 🙂

Get documentation: there is very few in the internet today.


There are several gnu versions available on the Internet, precompiled for PowerPC and for VxWorks. So this is easy. I installed an older version (gcc 2.9.6) that fits somehow to the VxWorks version 5.3.1 and compiled a hello.c:

//#include <stdio.h> extern int printf ( const char * format, … ); int main(void) { printf(„Hello, Worldn“); return 0; } void testPrint(void) { printf(„Hello, Worldn“); }

Note that I do not yet have a working stdio.h and can not use it so far. The packages on the net do NOT contain VxWorks libs or headers, because they are of course copyrighted.

With command line:

./ppc-gcc-296 -v  -fno-builtin -I ~/ics-files/devel/C/TornadoPPC/target/h/ -nostdinc -O -c -DCPU=PPC604  hello.c

A hello.o is created. The ppc-gcc-296 is a simple shell script that extends the path to find all the ppc compiler executables:

echo „ppc-gcc wrapper…“ PATH=/home/dennis/ppc/gcc/host/x86-linux/bin/:${PATH} powerpc-wrs-vxworks-gcc „$@“

Regarding options: -nostdinc suppresses the use of host-side standard  includes/headers.  I want that  only target-side headers are used and make the root to them known with -I <path>. -no-builtin prevents use of (host-side)  builtin functions. -DCPU=PPC604 is relatzed to my CPU model 604.

Note: No linking (no „ld …“) is required for VxWorks. It simply uses the .o files. (It is possible to use ld on the host to create a single .o-File from a set of .o-Files.)

VxWorks does not use the oncept of main-functions as entry points for the OS. To load the file on the target use:

ld <hello.o

value = 0 = 0x0

Now, all functions inside the .o file can be called simply by using their name (we have „main“ and „testPrint“):

-> testPrint
Hello, World
value = 13 = 0xd

So that was easy.  I have a working cross compile environment for the ICS-1000.

<to be continued>

Bastelecke: RS232 Signalanalyse mit einem Logikanalysator

RS232 wurde bereits in den 1960ern eingeführt und standardisiert. Die RS232 Schnittstelle ist hardwaremäßig und softwaremäßig sehr einfach gestaltet. Daher ist sie auch in einfacheren Umgebungen, z.B. bei Microcontroller-Anwendungen, gut einzusetzen.

Hier soll exemplarisch die Analyse des RS232 Signals eines PC-Motherboards mit einem Logikanalysator dargestellt werden. (Eigentlich möchte ich nur meinen neu erstandenen kleinen Thurlby-Logikanalysator testen und mache das an diesem Beispiel…). Außerdem wurde dasselbe mit einem Oszilloskop gemacht.


Auf den Leitungen des RS232 Kabels wird mit Spannungen von -12 V für einen High-Pegel und +12 V für einen Low Pegel gearbeitet, es kommt also negative Logik zum Einsatz. Spannungen unter -3 V werden als Low gewertet, und Spannungen über +3 V werden als High gewertet. Die Umsetzung von TTL-Pegeln auf RS232 Pegeln erfolgt mit Bausteinen wie MAX232. Datenleitungen liegen im Ruhezustand auf High.

PC-Schnittstellen benötigen aber im Allgemeinen die genannten Pegel (+/- 12 V) nicht. Meist kann man auch mit TTL-Pegeln arbeiten, wenn diese nur invertiert (in negative Logik überführt) werden. Dann gilt 0 Volt als High, 5 Volt als Low.


Die minimale Anzahl von Drähten für eine funktionierende RS 232 Verbindung besteht aus den folgenden Signalen:

  1. TxD des Senders an RxD des Empfängers (Pin 3 an Pin 2)
  2. RxD des Senders an TxD des Empfängers (Pin 2 an Pin 3)
  3. Gnd des Senders an Gnd des Empfängers (Pin 5 an Pin 5)

Es geht auch komplexer, mit Handshake-Leitungen, ist im Mikrocontrollerbereich aber nicht attraktiv, da dann mehr Port-Leitungen verwendet werden müssen.


Um mit der Minimalbelegung eine stabile Verbindung ohne Datenverlust zu realisieren, wird üblicherweise ein Software-Protokoll eingesetzt. Mittels der über die Leitungen gesendeten Signale XOFF und XON wird das Gegenüber zum Stoppen bzw. Fortsetzen der Datenübertragung aufgefordert. Wenn beide Seiten aber schnell genug sind, kann auch hierauf verzichtet werden.

Bytes werden bitweise sequentiell übertragen, LSB zuerst, MSB zuletzt. Sender und Empfänger müssen auf die gleiche Baudrate eingestellt werden, möglich sind Werte zwischen 300 Baud und mehr als 100 KBaud. Mangels Takt wird der Beginn eines Bytes fest mit einem Low angezeigt, dem Startbit. Dem Ende des Bytes folgt ein Stopbit, das immer High ist. Neben der Baudrate und der Anzahl der Stopbits (0,1,2) kann auch noch ein Parity-Bit übertragen werden. Die einzelnen Bits passen in das durch die Baudrate vorgegebene Raster. Zusammengefasst also die folgenden Eigenschaften:

  • Ein Startbit (Low)
  • Datenbyte: LSB zuerst, MSB als letztes (also: Bit 0, Bit 1, … Bit 7)
  • mindestens 1 Stopbit (High)

Im folgenden wird ein konkretes Signal analysiert. Das Signal wird am USART-Ausgang des Microcontrollers ATmega8 abgegriffen, besitzt also noch TTL Pegel und positive Logik.

Das Signal ist auf 19200 Baud eingestellt. Desweiteren ein Stopbit und kein Paritätsbit. Somit kommen auf ein Byte 10 übertragene Bit. Die Länge eines Bits berechnet sich t=1/f wobei f die Baudrate ist. Für 19200 Baud ergibt sich ein Wert von ca. 52 Mikrosekunden.

Analyse mit einem Oszilloskop

Oszilloskop Zeitablenkung wurde auf 100µs eingestellt. Dann passen etwa 2 Bits in eine Skaleneinheit. Dann wurde ein einzelner Buchstabe ‚a‘ gesendet. Dieser entspricht hexadezimal 61h und 0110.0001 dual. Da die Bits LSB first gesendet werden, wird ein Bitmuster …1000.0110… erwartet.

Buchstabe ‚a‘. Gemessen an einem AVR der mit 3,3Volt betrieben wird.

Oben sieht man das Startbit (Low), ein High Bit, 4 Low-Bits, 2 High Bits, 1 Low Bit und den Übergang zurück nach High. Zusammngestellt also:


Fett dargestellt wurde die gesuchte Bitfolge „1000.0110“. Dies ist unser ‚a‘ mit LSB first. Die ‚0‘ davor ist das Startbit, die ‚1‘ danach das Stopbit.

Insgesamt also genau das erwartete Ergebnis.

Analyse mit einem Logikanalysator

Der Logikanalysator wird auf 100 Mikrosekunden Periodenlänge eingestellt. Er wird an RxD, TxD und Gnd angeschlossen. Ein Testprogramm gibt kontinuierlich eine Zeichenfolge („ABC”) auf TxD aus.

Oben Logikanalysator, unten Oszilloskop (Der abgebildete Logikananlysator gibt  sein Videobild über einen Oszilloskop aus)

Der Logikanalysator wird gestartet und nach kurzem unterbrochen. Sein Speicher ist nun voll mit den Signalen der Schnittstelle. Eine Übertragung der High/Low Pegel in eine Eins-Null-Folge bringt folgendes Ergebnis, das aus dem Analysatorspeicher wahllos herausgegriffen wird:

10 0 01000010 1 0 110000101 0100000110 10010000101 011000101 0100000101 0010000101 0110000100101000

Die gewählte Gruppierung erfolgte beliebig.

Die Buchstaben A, B und C sehen als Bitmuster inklusive Start/Stopbit wie folgt aus:

Hex Bitmuster mit LSB zuerst

A 41 0 1000 0010 1

B 42 0 0100 0010 1

C 43 0 1100 0010 1

Der Vergleich der Bitmuster mit dem Ausschnitt aus dem Analysatorspeicher ergibt folgendes:


0 0100.0010 1 = B

0 1100.0010 1 = C

0 1000.0011 01 = A das zweite High dauert länger

0 0100.0010 1 = B

0 1100.010 1 = C das dritte High dauert zu kurz

0 1000.0010 1 = A

0 0100.0010 1 = B

0 1100.00100 1 = C das 6. Low dauert länger


Man kann erkennen, dass die Daten nicht perfekt geliefert werden, sondern leichte Variation haben. Pegel dauern etwas zu lange oder etwas zu kurz. Das bügeln die Schnittstellenbausteine aber normalerweise aus. Bei Experimenten zwischen AVR Controller und PC konnten Zeichen durchaus auch dann noch in Teilen richtig übertragen werden,  wenn die Baudrate falsch eingestellt war.

Das Lesen der Pegel erfolgt durch die Schnittstellenbausteine genau in der Mitte eines Bits, diese Mitte kann aber der Logikanalysator nicht anzeigen. Es gibt somit auch eine Ableseungenauigkeit am Logikanalysator.

Abgebildet sind 8 Dateninputs des Analysators,  mit dem Signal ist nur der untere Eingang belegt


Insgesamt zeigt der Analysator das erwartete Ergebnis und mit etwas Mühe kann ein RS232 Strom nach Aufnahme durch den Logikanalysator „per Hand” analysiert werden. Auch Detailbetrachtungen mit dem Oszilloskop sind einfach möglich. Da die Speicherdaten aus dem Analysator in einen PC übertragen werden können, kann die Analyse dort automatisiert fortgesetzt werden.