Tektronix5014C keeps data in buffer

[fvanriggelen]

If you encounter a bug use the following template. If you have a feature request feel free to freestyle.

Steps to reproduce

1. send commands to AWG
2. restart the console after error, when apparently the command is not executed
3. reinitialize AWG
4. send new command to AWG
5. result: mismatch between most resent send command and command being executed by the AWG

Expected behaviour

Adapt the driver of the AWG in such a way that it clears the communication with the computer when it is initialized

Actual behaviour

Keeps old commands in communication channel, causing confusion of what command is being executed

System

operating system Windows 7

qcodes branch master

qcodes commit 83542518f422b18d2d4c31ad2d5655049164ef8a

@CumulonimbusCalvus

[WilliamHPNielsen]

I think this is a general problem with VISA communication and can be reproduced on most instruments by simply issuing a write command with a query string and neglecting to read back the answer. Now the VISA message queue is out of sync.

One obvious solution that's actually been on my mind for a long time is to extend the QCoDeS VisaInstrument with a clear_message_queue method. Incidentally, the driver in question, the AWG5014C, already comes with that method. @fvanriggelen, you can make sure to call that method when needed.