Clearing RS232-GPIB Prior to sending commands to Agilent N3300A

[Tim_C.]

I have been trying to communicate with an Agilent N3300A DC Load Bank via a CRIO 9012 Com port and NI GPIB-RS232 converter. 

The communications is somewhat buggy and the instrument does always do as instructed.   I have tried adding time outs (which should not be required but that does not help.

How do I flush the RS232 converter ahead of every command in the hope this will help clean up the communications between the CRIO and GPIB instrument?

Thanks

Tim C.