After writing instrument MLA address to CDOR of NAT7210, how do I send a command like SYST:BEEP

[Alex7210]

This is our first time to use GPIB. I am using NAT7210 as GPIB controller in a custom microcontroller circuit and have a problem sending commands like SYST:BEEP. The sequence of events are as follows:

1) The REN line is asserted by writing sre $1F command to AUXMR. I verified the REN line on GPIB connector is asserted by the NAT7210 after this command.

2) The rqc ($08) command is written to AUXMR to bring NAT7210 to active CIC mode. I verifed the ATN line on GPIB connector is asserted by the NAT7210 after this command.

3) The MLA address of instrument is written to CDOR of NAT7210. 

4) The instrument receives this data correctly by indicating on its front panel that it has just been addressed.

5) The gts ($10) comand is written to AUXMR to bring NAT7210 to Standby CIC mode

6) The ascii SYST:BEEP<lf> is written to CDOR of NAT7210

7) The instrument is not responding to the SYST:BEEP command.

I have tried other commands like *RST but no response. Can anyone help what are we missing?

[Alex7210]

OK, I saw what I was missing: I forgot to send the MTA command together with the MLA before doing the gts. Apparently GPIB devices will respond to the MLA command and proceed to remote mode if it hears its address but it wont decode any commands if the talker did not identify itself. Just an FYI here in case someone out there might find this useful.

Now we can get our work started... 

[Scott-M]

Thanks for posting your solution Alex, I am sure others will find it useful!

Scott M.