Specifications

Operations Manual, Redundant System Controllers 209351 REV B 73
7.1.2 Control Inputs
The parallel control inputs are opto-isolated inputs with pull up resistors. To trigger a
remote input command, the input should be pulled to ground. The input does not need
to be held to ground continuously but it is acceptable to do so. The input only need be
pulled low for a minimum of 100 msec. For example, to make amplifier #2 the standby
amplifier, pulse pin 36 to ground for 100 msec. If the operator then chooses to make
amplifier #1 the standby amplifier, simply pulse pin 37 to ground for 100 msec. The
schematic representation of the control input is shown in Figure 7-3.
The external alarm and auxiliary alarm inputs use the same opto-isolated input circuitry
shown in Figure 7-3.
3.3K
560
+5 VDC
Control Input
Opto-Isolator
Transorb
Figure 7-3: Opto-Isolated Parallel I/O Input