Manual - 8500A Series Peak Power Meter - Giga-tronics

Remote Operation
When the PPM has drawn a complete pulse profile on its display, it is ready to act as a GPIB controller.
When the plot routine is activated, the PPM checks to make sure that there is no other active controller
on the bus. If the PPM is in the Remote state, it implies that a controller is present and registers as a
GPIB bus error. Also, all PPM service requests are generated by action on the GPIB, and are cleared
when REN is not asserted (see Remote and Local Lockout in Section 3.2.4). Therefore, if the PPM
internally detects any abnormal status condition in its status byte, it will assume that there was recent
activity on the bus involving a controller and refuse to proceed further with the plot. It will also attempt a
service request to see if there is any response from the controller.
If the PPM does not detect an indication of another controller, it will assume that it is the only
controller-capable device on the bus, and will act as the system controller. Depending on the system
configuration, these checks made by the instrument may not be perfect.
☛ NOTE: For proper system operation, no active controller can be on the bus when the front
panel function is initiated.
While the PPM is checking the state of the bus, it will display the message Checking GPIB Interface, and
the keyboard will be inactive.
If the PPM does detect an indication of a controller on the bus, or if the PPM takes control of the bus and
attempts to address the plotter but does not get a handshake, a GPIB bus error message will be displayed
and a prompt will require F2 to be pressed to continue. If the PPM does not detect a bus error, a beep
will sound and normal operation will resume while the plot is being sent over the GPIB. Once plotting
has begun, control of the front panel will be returned to local.
☛ NOTE: If you want to add serial and code numbers to the plot, use the procedure for
Making Plots in Section 2.9.
Manual No. 20790, Rev C, November 1998 3-11
Superceded by Revision D, March 2009