"device clear" in asyn/Gpib support.

[Noboru Yamamoto <noboru.yamamoto@kek.jp>]

Hi,

I have a device through vxi-11 over ethernet.
I need to send "device clear" message/command to this device to
cancel an operation.

I use an asyn/GP-IB/vxi-11 based device support and set gpib command 
table entry as:

 {&DSET_BO, GPIBDCL, IB_Q_HIGH, NULL,  NULL,  0, 0, NULL, 0, 0, NULL, 
NULL, NULL }.

This setup send a DCL universal command to the device through vxi-11 
"device_docmd" rpc function.
Unfortunately, our device does not support this method. The device just 
accept "device_clear" rpc call but not "DCL universal command".

In the current asyn package, each IFC and REN has an entry in an 
asynGpibPort structure, but DCL(Device Clear) is treated as one of 
universal commands.

It would be possible to introduce a new entry in asnyGpibPort for DCL
and call "device_clear" rpc function in the handler for vxi-11.
But I'm not quite sure if it does not break existing applications.

I would appreciate any comments or suggestions to solve this problem.

Thank you for reading this message.

Regards,

Noboru Yamamoto
EPICS group, Acclerator Lab.
KEK, JAPAN