Synchronizing Power Module Output Changes 57
5
Synchronizing Power Module Output Changes
Introduction
If you use only the VOLT [: LEV] : TRIG and/or CURR [: LEV] : TRIG commands to trigger output changes, you do not need the
information in this chapter. This chapter gives supplemental information on how you can synchronize power module output
changes to internal or external events. The output changes can be:
•
A change in output voltage level.
•
A change in output current level.
•
The start of an internally-paced list of output voltage or current levels.
•
A step to the next level in a list of output voltage or current levels.
•
A change in the output state (on or off).
The event to which the output change is synchronized can be any of the following:
•
A command from the controller.
•
A GPIB bus command.
•
An event that occurs within the power module.
•
An event that occurs within another power module.
•
An external signal at the mainframe trigger input.
•
An external signal at the mainframe fault inhibit input (INH).
The output synchronization is implemented by the following power module functions:
•
Trigger subsystem.
•
List subsystem.
•
Remote inhibit (RI) subsystem.
•
Discrete fault indicator (DFI) subsystem.
Trigger Subsystem
Two simplified models of the trigger subsystem are presented. The first model shows how the trigger subsystem functions
during fixed-mode output. This mode occurs when VOLT:MODE FIX or CURR:MODE FIX is in effect (see "Chapter 3 -
Language Dictionary"). In this mode of output control, each triggered output voltage or current value is explicitly specified
by a triggered-level command (for example, VOLT: TRIG 20 or CURR: TRIG 1.55). The trigger then causes the output to
change to this pending triggered level.
The second model shows the difference in trigger subsystem operation during list-mode output. This mode occurs when the
VOLT:MODE LIST or CURR:MODE LIST command is programmed (see "List Subsystem" further in this chapter for an
explanation of lists). In this mode of output operation, the triggered output voltage or current levels are specified within a
list and the trigger controls the sequencing through the values in the list.
Model of Fixed-Mode Trigger Operation
Figure 5-lA is a simplified model of trigger subsystem operation when the power module is programmed for fixed-mode
output. The rectangular boxes represent states. The arrows show the transitions between states. These are labeled with the
input or event that causes the transition to occur.
