Synchro Resolver Simulator (SIM-31200)

[Srm27]

Hi,

I hope someone can help?

A DDC SIM-31200 has come across my desk in integrate into our test setup.

This is a Synchro Resolver Simulator

I am trying to connect to the GPIB of the unit but with very limited success.

Has anyone connected remote via GPIB and got it working?

Thanks

Simon

[Rob_Ward]

Dear Simon,

I have looked into your problem, and managed to find a bit of info on the instrument you are using.

From the information you provided I understand your problem to be that you have your DDC SIM-31200 instrument communicating with your computer through a IEEE-488 GPIB interface bus.  I have not been able to find any instrument drivers for the product you have, so I think that you will have to use VISA (Instrument I/O) to configure your equipment manually.

I would reccomend using Measurement and Automation Explorer (MAX) to test your device using the primary and secondary addresses.  Try passing some command functions to the instrument to see if you can communicate with the instrument OK, and that the commands behave as expected (see pages 8 & 9 of http://www.teknetelectronics.com/DataSheet/DDC/DDCSIM_31200.pdf ).  If so, then you can write some sub-VI's using VISA to act as your basic read & write functions inside your main program.

Here is a useful doccument for getting to grips with VISA; http://digital.ni.com/public.nsf/allkb/FAA8A8583318B75B8625737C005CB81D?OpenDocument

I hope that this helps in some way to solving the problem you are having.

Regards,

[Srm27]

Robert,

Thanks for that, but even the basic commands for GPIB or from the manual do not work.

There is one thing in the manual I did see so maybe someone could help as this might be the root of the problem.

On the DDC SIM-31200 instrument Pinout on J2, GPIB connector, table 2-2, pin 7 is RDF and pin 8 is DAC.

Any documentation I have seen for GPIB name pin 7 NRDF and pin 8 as NDAC.

As this equipment is over 15 years old and obsolete was there a change in pin designation for the GPIB bus?

Thanks

Simon

[Rob_Ward]

Simon,

I woulb be surprised if the GPIB has changed without there being much documentation about it on the web.  You aren't by chance using a GPIB-ethernet bridge by any chance are you?

Reason being is that it is an interesting point you make about RFD and NRFD (pin 7).  I have noticed that on the GPIB that pin 19 is the Ground NRFD which led me to the fact that the male plug and female jack are crossovers, and I know that ethernet is a crossover platform; so I am just wondering if that may be it.

Regards,

[Rob_Ward]

Simon,

have you been able to make any progress with this yet?  I noticed that if you go to the functions palette > Instrument I/O > GPIB > GPIB 488.2 then there are several low level functions that you can use to test the communications with your instrument.

Let me know if you make any progress or if you are still stuck on this.

Regards,

[Srm27]

Robert,

Thanks for your intrest.

We have a test setup, in use, with GPIB card running on Windows 98 which will detect the equipment on the correct address.

On trying to issue ANY command via the assistant it will always time out.

We also have a USB to GPIB interface, from Prologix. This is seen as a serial port on the PC.

On monitoring the serial port for this device once ANY command is issue the equipment is always transmitting carriage returns (0D) and line feeds (0A). We are using a port monitor program to see the activity on the serial port.

We are now looking into the possibility of using the other connector which also provides some sort of remote control, PRL, new to me.

Again Thanks

Simon

[Rob_Ward]

Simon,

Just quickly, I read the Prologix GPIB USB manual available from their website (http://prologix.biz/gpib-usb-controller.html), and I read on page 8 that "All commands start with the "++" character sequence.  Commands must be terminated with CR or LF".

Could this be why you are getting timeouts or have you already been doing this?

Regards,

[Srm27]

Robert,

Thanks for that.

I have two different setup's.

One on W98 with a PCI GPIB card giving timeouts, and a second XP PC with the Prologix returning CR and LF on the issue of a command from the PC, but not carrying out the required instruction.

The Prologix is working on other equipment it has been tried on. 

Thanks

Simon

[Rob_Ward]

Simon,

I did some reading about the GPIB IEEE-488 standard, and all I could find is that when the standard was updated to 488.2 it was designed to be backwards compatible.  I suspect that the instrument drivers you have are 488.2 so can't see why this would be a problem.

All I can figure now is to try to get in contact with the instrument manufacturers and ask them about the differences in pin assignment you mentioned to see if they can shed any light on this situation.

Keep me posted with any developments

Regards,

Rob

[Rob_Ward]

Dear Simon,

have you had any luck since last time?  Have you been able to get in contact with the manufacturers?

Regards,