The B1500A is not responding to the GPIB queries that I am sending it. What am I doing wrong?

You need to have the following two conditions satisfied in order to control the B1500A through its GPIB interface:

1. The B1500A must be set up to be “not a system controller.” To verify this, first make sure the “Start EasyEXPERT” window is NOT showing (i.e. the process is not running in the background). Next, start up the “Keysight Connection Expert,” which is located under “Programs…Keysight IO Libraries Suite.” Select the “USB/GPIB (GPIB0) item in the menu tree to view the instrument status or to change its properties. A reboot is required if you change the instrument properties.
2. The “Start EasyEXPERT” window must be showing on the Windows XP main screen (i.e. the process must be running in the background). However, DO NOT click on this window to start EasyEXPERT on the B1500A, as you cannot control the B1500A remotely when the main EasyEXPERT window is running on the instrument.