Access to Gpib Address via record in ASYN

[Andrew Wagner <apwagner@u.washington.edu>]

Hi everyone, 

I would like to access the Gpib address of a record within an ASYN devGpib device driver. I would like to use this information in custom messages to be sent to the physical device. Specifically I am writing drivers to communicate to several Gpib devices controlled with a PROLOGIX Gpib to Ethernet controller. The controller issues Gpib commands to the last device addressed to it via a custom command ++addr # (where # is the Gpib address of the device you want to address). Presently if multiple devices are under the control of a single PROLOGIX the individual Gpib addresses must be hard coded into the driver messages. i.e. 

  {&DSET_SI, GPIBREAD, IB_Q_HIGH, "++addr 19\n*IDN?\n++read eoi",NULL, 0, 200, NULL, 0, 0, NULL, NULL, NULL}

gets the IDN from Gpib Address 19 and 

 {&DSET_SI, GPIBREAD, IB_Q_HIGH, "++addr 24\n*IDN?\n++read eoi",NULL, 0, 200, NULL, 0, 0, NULL, NULL, NULL}

gets the IDN from Gpib Address 24. 

I would like to be able to access the Gpib Address (A) defined for a record in the OUT or INP fields, i.e:

field{OUT, "#L$(L) A$(A) @2) 

via something like 

 struct aiRecord *pai= (struct aiRecord *)pdpvt->precord;

 int addr = (int)pai->A; 

Unfortunately, searching through the API documentation I couldn't find how to access the Gpib address in the record struct. The codes a little dense so I could easily have missed something. I've had a lot of success with the PROLOGIX controllers and hard coding Gpib addresses definitely works, its just inelegant and unportable. Thanks for your help and advice. 

Andrew Wagner