User`s manual

26 Configuring the Relay Multiplexer Modules Chapter 2
Selecting the Interrupt Priority
The multiplexer modules generate interrupts after a channel relay closing or
opening completes. These interrupts set the selected line on the VXI
peripheral interrupt bus true.
The VXI peripheral interrupt bus consists of 7 interrupt priority lines that
carry the interrupt signal to the commander. Line 1 has the highest priority
and line 7 the lowest. The multiplexer module's default setting is line 1, since
it is the most commonly used interrupt line.
The E1300A/E1301A Mainframe default operation is to monitor all seven
interrupt lines. The E1405B/E1406A Command Module's default operation
is to manage only one line. The Command Module does, however, use an
interrupt line allocation table that allows you to select which lines the
command module is to monitor. For embedded controllers, refer to the
appropriate controller documentation to determine which of the line(s) the
controller monitors.
When using an E1300A/E1301A Mainframe or E1405B/E1406A Command
Module for register-based programming (instead of the SCPI driver) and
where the program generates an interrupt, be sure to use the multiplexer
module's interrupt line that does not interfere with the program. Use the line
that is not used by the SCPI driver to generate interrupts.
Refer to Figure 2-4 to change the interrupt priority. Unsolder and remove
two jumpers from the old priority location. Install the jumpers in the new
priority location (Figure 2-4 shows a priority change from 1 to 7).
Figure 2-4. Changing the Priority Interrupt Level Jumpers