NI Home > Community > NI Discussion Forums

Instrument Control (GPIB, Serial, VISA, IVI)

Reply
Member jey
Member
jey
Posts: 21
0 Kudos

HPIB instrument is not responding

Hi ,
I need expert advice in making out my project comleted.Now i got stuck up with problems in communicating with a GPIB instrument(HP-IB bus).
Software and Hardware Used:
Driver:NI 488.2 Ver 1.70,
Board: PCI-GPIB
Troubleshooting/Configuration Tools:MAX,Interactive Control,NI-SPY

Overview of the Instrument:

This instrument is a GPIB interfaced 8085A based embedded system which should respond some 15 commands. These
commands can be summarized for 2 reasons(Just for information).1.RF band selection 2.Signal amplifier(TWTs) Status and their fault reset.I can do these operations either through front panel keys(local mode) of the instrument or through GPIB device specific commands(in the remote mode).Sadly, my FRONT PANEL KEYS ARE WORKING correctly not the GPIB commands.The instrument is interfaced with HP-IB 488.1

Troubleshooting Procedure what i followed:

1.Through MAX I did scan for instruments and could get the Primary Address(13) of the instrument with "Instrument did not respond to the *IDN?"(This could be bcoz of the instrument does not support IDN command).Then started communicating with the instruments.When i tried writing commands,they are accepted as Count is showing No of Bytes written correctly(with iberr=0) .Interestingly,it is takingin every other string than the specified commands also.(suppose if i write "jeyaseelan" its returning Count=10 iberr=0).Every read and Query commands returning EAB0 of iberr with ERR bit set in the status Byte with timeout error.

2.Then i opened Interactive control I gave the PCI-GPIB System-in Charge(ibrsc),then cleared the interface(ibsic),remote enable(ibsre).Then checked if Intrument is Listening at address 13.It returned LISTEN:TRUE.Opened device handle with 10Sec timeout with EOI true.Then i started writing commands.ibwrt"rst" or "llo" or "BND06"(Device Specific).The behaviour is same as the above.

ibwrt:-Accepting all strings not just commands with iberr=0.The true commands written are not behaving in a way they should be .If i have sent Local Lok out command"LLO".I could still operate the instrument through the front panel Keys that it should not be.

ibrd and Qurries: EAB0 for iberr with ERR set in Ibsta status register.
I have attached the NI SPY Data Log File .Unfortunately i did not log for the read and query operations(bt they behaved exactly what i mentioned above) but only for the write operation.

Documentation of this instrument is not very much clear about the SEQUENCING of commands.It deals mainly with the functionality of the commands.I am guessing Command parsing part of the firmware is not functioning at all.

Please let me know where the problem may be and how to correct it .Whether i could use the same instrument in the existing system set up for the remote operation?


Thanx

Jey
jeyaseelan P
AutoTEC Systems Pvt Ltd,
Bangalore-46
Member
JenK
Posts: 160
0 Kudos

Re: HPIB instrument is not responding

Hi Jey,

You mentioned that you attached the NI-Spy capture, however I did not see it. Can you attach it again? I'd like to look at it to see what's going on. I don't know right off what's going on, but I'll definitely take a look at it.

JenK
Member jey
Member
jey
Posts: 21
0 Kudos

Re: HPIB instrument is not responding

Thanx for your response JenK.Herewith i have attached the NI SPY capture file.It does have only the write calls i made.Read and Query commands returned with errors and the exact behaviour of these read/query commands, i have mentioned on my previous postings.If these information are not sufficienct please let me know as i need your answers to proceed to the next step .

jey
jeyaseelan P
AutoTEC Systems Pvt Ltd,
Bangalore-46
Member
JenK
Posts: 160
0 Kudos

Re: HPIB instrument is not responding

Jey,

I'm not quite sure why you are receiving the behavior that you described, it doesn't make much sense. What is the exact instrument that you are using? You mentioned it is a GPIB interfaced 8085A and you also said it was a HP-IB 488.1 interfaced instrument. Can you provide a little more information about your setup?

I noticed that you said you were using NI-488.2 v. 1.70. There is a newer driver that you can download from National Instrument's website, version 2.3. You can get it here. I would suggest installing this latest driver, version 2.3 and see if that makes any changes to the behavior. I will continue to look into this and let you know if I find anything.

JenK
Member jey
Member
jey
Posts: 21
0 Kudos

Re: HPIB instrument is not responding

Hi JenK ,the system is a old one . I think I got confused with different flavors of IEEE 488,when i mentioned HP-IB 488.1.All are HPIB interfaced instruments with a HPIB extender in between and were controlled by a HP-9800 computer running BASIC application.This application is now crashed .Now i should replace the HP-9800 computer with an industrial PC running LabView application over windows.And to that, i should use GPIB-ENET in place of extender.Back to the instrument ,it is a minicomputer running over Intel 8085A processor interfaced with HPIB.From the PC point of view it is just another instrument interfaced with HPIB. I have added a figure with this to have a basic view of the system.Mean time i try out with this new version of NI GPIB driver and get back to you with the data logs in few days.

with regards,
Jey
jeyaseelan P
AutoTEC Systems Pvt Ltd,
Bangalore-46