Hi,
we use a NI 488.2 card as a slave (Listener and Talker), with the dll and our own code.
The problem is, that it is not working reliable. We tried it as described in the NI-488.2 User Manual,
Section 8-12, the code does the following:
Init:
(*Pibonl)(mGPIBDesc, 1); /* Set Board online */
(*Pibeot)(mGPIBDesc, 1); /* Auto assert EOI Line at the end of write ops */
(*Pibrsc)(mGPIBDesc, 0); /* Release System Control (Configure the GPIB board to NOT be a system controller) */
(*Pibconfig)(mGPIBDesc, IbcSAD, GPIBSAddress);
(*Pibconfig)(mGPIBDesc, IbcPAD, GPIBPAddress);
Loop:
while(1) {
aStatus = (*Pibwait)(mGPIBDesc, 0xC0BF);
if (aStatus & ERR) {
LOG_E("GPIB Error!")
printf("ibstat: %x, iberr: %x\n", aStatus, *Piberr);
} else if (aStatus & LACS) {
(*Pibrd)(mGPIBDesc, recbuff, RECBUFFSIZE);
if ((*Pibsta) & ERR) {
LOG_E("GPIB Read Error!")
printf("ibstat: %x, iberr: %x\n", *Pibsta, *Piberr);
}
recbuff[(*Pibcntl)] = 0;
printf("Received: %s\n", recbuff);
} else if (aStatus & TACS) {
(*Pibwrt)(mGPIBDesc, sendbuff, SENDBLOCKSIZE);
if ((*Pibsta) & ERR) {
LOG_E("GPIB Write Error!")
printf("ibstat: %x, iberr: %x\n", *Pibsta, *Piberr);
}
}
} else {
printf("IBWAIT: ibsta: %x ++++++++++++++++++++++++++++++++++++++++++++\n", aStatus);
}
}
It works as long as the device gets only talk request, as soon as there are listen requests, too, there
are timeouts, because the code calls ibwrt again and again since the TACS bit seems to stay at 1
even after a successful write. It times out since there is no longer a listener active.
What we need is some listen and talk stuff (*IDN?) and reading out strings of our device acting as a
slave. Is it possible to get this working reliable with a NI-488.2 card so it fulfills IEEE 488 and does not
only work sometimes
If not, is there a PCI Card available that can do this reliable?
I have read
http://forums.ni.com/ni/board/message?board.id=140&message.id=9749
and found there a solution with asyncronous calls, but how can one stop a pending ibwrta?
Is this a reliable working and full standards compliant way?
Is example source code available from NI for a working slave?
Thanks in advance.
Best regards,
Steffen
