12-11-2008 04:23 PM
12-12-2008 01:51 PM
MGotcha,
I am investigating this.
Regards,
12-12-2008 04:12 PM
Hello MGotcha,
At first I was trying to think of any other instruments that do this kind of behavior, but I ended up not being able to do this. Instruments usually respond to queries from the host. If there is no query, there is no way for the instrument to know how to respond. The only consession for extra data being sent across the bus (data not attached to a query) is for instruments to signal SRQ when extra data is ready. You may want to use service requests when extra data is ready on your instrument instead of simply responding when you think that the controller is listening again.
If you decide that the behavior you described is correct for your system, I think I know of a way to work it in. NRFD is the first handshaking line to toggle when a listener is expecting data. You can check the state of NRFD (to see if there is a listener), check the state of the ATN line (to make sure that command bytes are not getting sent out), and make sure that your instrument is still addressed as talker.
I have not fully thought out how this would work if there were multiple instruments on the system, but it is possibly a better work-around than the one you are currently using.
I hope this helps,
Steven T.
12-12-2008 04:14 PM