GPIB-232CT-A serial protocol

[marlanbrando]

Hi:

We have the following two possible setups currently:

Setup #1

Windows XP machine with NI's PCMCIA-GPIB interface card   <----- GPIB ---->  { item A } <serial> <----> custom software

Setup #2

Windows XP machine <--- serial port ---> NI's GPIB-232CT-A   <----- GPIB ---->  { item B } <serial> <----> custom software 

Basically, the legacy software running on the Windows XP machine can talk with either NI's PCMCIA-GPIB interface card or NI's GPIB-232CT-A.

We can't change the software that is running on the Windows XP.

We need to prototype software in 8 weeks that show we can talk with this legacy software running on the Windows XP machine.  The problem is that the custom software on the right hand has a custom OS and due to time, we can't write any custom device drivers nor anything too time consuming.

We can choose to use either setup #1, setup #2, or even possible setup #3 where NI's GPIB-232CT-A is removed from setup #2 leaving a direct communication via serial between the Windows XP machine running the legacy software and the custom software.  The problem is that the legacy Windows XP machine would be running the legacy software that is trying to talk with NI's GPIB-232CT-A that would normally be there and our custom software would have to handle the protocol for that to mimic that communication if we choose that route.

Can someone or NI offer the best suggestion to handle this problem?  Would it be simpler if we add to {item A} or {item B} one of your other products inline to convert from GPIB back to serial and no drivers are required for our custom software where we can directly talk with your device?  I think NI had a GPIB-232CV-A protocol converter at one point for something like that.  Would that be the easier route?  Or would be it easier to take out the GPIB-232CT-A and allow the serial communication to occur but what we have the custom software talk with the Window XP machine's legacy like it was the GPIB-232CT-A was there.  But it would involve knowing the protocol between the legacy software and the GPIB-232CT-A???? 

Any suggestion would be much appreciated.

[A_Ryan]

marlanbrando,

I have some additional questions for you, to help clarify your particular situation:

1.  Can you please explain what you mean by legacy software?  Is this old NI software or some other third party software? 

2.  Is the system setup and a current problem already exists?

3.  Are you in the development stage and wondering how to proceed?

4.  What do you mean by prototype software (what does it do)?

5.  What is your application/what is the ultimate goal?

[marlanbrando]

Hi A_Ryan:

<1.  Can you please explain what you mean by legacy software?  Is this old NI software or some other third party software? 

The "legacy software" is written in Java and is running on a Windows XP Pro machine.  This "legacy software" was designed to communicate via either with NI's PCMCIA-GPIB interface or NI's GPIB-232CT-A device.  Legacy meaning existing software controller application that won't be changing.

<2.  Is the system setup and a current problem already exists?

The existing system works just fine.  The problem is on the other end where DeviceX is no longer a GPIB device.  But for backward compatibility purposes, we need DeviceX to still be able to communicate with the "legacy software" running on the Windows XP Pro machine.  DeviceX is an embedded device and thus it is running a custom OS.

<3.  Are you in the development stage and wondering how to proceed?

We are in the early development stage and just verifying how we can ensure backwards compatibility as described above.

<4.  What do you mean by prototype software (what does it do)?

Simply just verifying that DeviceX, which is not a GPIB device but does have serial port and cannot install any NI drivers, can somehow communicate with the "legacy software" on the Windows XP Pro machine.

<5.  What is your application/what is the ultimate goal?

We have a DeviceX that does not have a GPIB input and has a custom OS.  DeviceX will talk with the new generation controller via some new interface but at the same time, DeviceX needs to still communicate with the Windows XP machine that is running the "legacy sofware" somewhere.  Because the "legacy software" was designed with GPIB in mind by interfacing to either NI's PCMCIA-GPIB card or NI's GPIB-232CT-A device.  One thought was maybe NI's previous serial-to-GPIB protocol converter device which doesn't require any drivers.  We could possibly connect this to DeviceX's serial port and the your serial-to-GPIB protocol converter device would then be connected to the NI's PCMCIA-GPIB interface on the other end.  Another idea, was to remove NI's GPIB-232CT-A device from the Windows XP machine and connect directly the Windows XP machine's serial port to the serial port of deviceX.  The problem is that the unchanged "legacy software" running on the Windows XP machine will still be communicating as though the GPIB-232CT-A device is there as the software was designed to so that puts the burden on the new software running on deviceX to mimic what would be the communication that the GPIB-232CT-A would have provided.  Seems more risky to do as we have to complete this in about a 2 months development timeframe.  Any suggestions?

[A_Ryan]

marlanbrando,

It sounds like you already have a viable solution to your problem.  Based upon your current setup, using the GPIB-Serial converter should work.  However, this makes the assumption that the legacy software is not hard coded for a specific GPIB device.  Here is the link for an NI GPIB-RS232.  This could be a possible device that converts GPIB-Serial for your particular situation.

[marlanbrando]

For the NI GPIB-RS232 that you recommended, we don't need drivers for it on DeviceX, correct?  So it will basically convert between GPIB and RS232 for DeviceX with DeviceX not requiring any special drivers to be installed for use with NI GPIB-RS232? 

[A_Ryan]

marlandbrando,

You are correct, you will not need any additional drivers.  However, you will need to know the commands for DeviceX in order to communicate with it.

[marlanbrando]

I was looking at NI GPIB-Serial Converter help document and they list functions such as the S Mode Functions such as cac, caddr, clr, cmd, eos.  So for our case where DeviceX is never a controller, we would just operate under D Mode and thus your device would act solely as a GPIB-serial protocol converter?  Can you confirm.  Thanks again for your help!

[A_Ryan]

marlanbrando,

That is correct, in D-mode the device will act as a converter from to GPIB-Serial.  Based upon the NI-GPIB-Serial Converter help, the D-mode section maybe very helpful for your particular application.

[marlanbrando]

Do you know if the GPIB connector end of National Instrument's PCMCIA-GPIB cable, part number 186557-01, would plug directly into the GPIB connector on the NI GPIB-RS232 device's connector?  Or do we need an adapter?

Thanks. 

[RayFarmer]

Hi,

The GPIB socket is standard and any GPIB cable with a GPIB Plug will mate correctly to it.

Hope this helps

Regards

Ray Farmer