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