I have written an OpenVMS socket based communication package to interface with our proprietary database and have observed behavior that I would like clarified if possible.

After connecting to the DT81 and sending an unload request for data from a 1 minute schedule's most current data (details omitted), I then read my socket and found "host computer return data" that continued to be sent for all schedules as they executed.

I corrected the problem by assigning the "NR" option to all of the variables in the schedules. I chose this method because I read on page 86 of the dataTaker User's Manual that the return, echo, error message, and alarm message switches were disabled during unloads.

Is the documentation referring to disabling by the unload command or by the vendor software that explicitly sends "/r/e/m/z". My assumption is the latter. The "practical" reason that I ask is that I would prefer to send the switches myself and maintain the ability to return these messages to other connections.

Good Afternoon skaar,

Yes you can use the switches to turn messages etc on and off. If a switch is upper case then it is on and lower case is off:
/e will turn off the echo
/m turn off messages
/r turn off real time data return
/z turn off alarm messages

so

/e/m/r/z UA

Will unload the data from schedule A, when the unload is finished you can then send /E/M/R/Z

If you are writing your own software you may want to use fixed format mode. This will ensure the data will alway come back in a known format. All our software uses fixed format mode for data return and status14 to work out how the logger is configured.

Cheers,
Roger