12 Keysight 34921A-34925A User’s Guide
– The simulation mode applies to the entire mainframe and cannot be selectively 
used on individual modules. 
– When the simulation mode is enabled, the Analog Bus relays will appear to 
close and open as directed. For example, no errors are generated if you close 
an Analog Bus relay from the front panel, remote interface, or Web Interface. 
However, remember that the Safety Interlock feature prevents the actual 
hardware state of the Analog Bus relays from being changed. When you 
connect a terminal block or cable to the module, the Analog Bus relays will be 
closed. 
– The simulation setting is stored in volatile memory and will be lost when power 
is turned off. To re-enable the simulation mode after power has been off, you 
must send the command again.