Symmetricom 58502A - Manual (Page 50)

Chapter 3 Features and Functions
Outputs
3-4 User’s Guide
ALARM/STATUS Port
This DE-9P (male) subminiature D connector or port allows you to
monitor the status of the 58502A via pins 2, 3, and 4 (see Table 3-1).
This port also allows you to receive compatible BITE (Built In Test
Equipment) alarm inputs from the 58503A GPS Time and Frequency
Reference Receiver and the HP 5071A Primary Frequency Standard
via pins 6 and 7.
The pin assignments are described in Table 3-1.
See the section “Different Ways to Check Alarm Status,” which
discusses three different ways you can check the alarm status of the
58502A.
ALARM/STATUS Port Outputs
The output pins (2, 3, and 4) of this port, shown in Figure 3-1, allow
you to monitor the status of the 58502A. Output pins 2, 3, and 4 are a
TTL high (3.5 Vdc, minimum) when operation is normal, and TTL low
(1.5 Vdc, maximum) if there is an alarm.
Figure 3-1. Alarm Outputs
All of the output pins are at a TTL high when there is no alarm
condition. When an alarm condition exists, all of the output pins drop
to a TTL low. These outputs echo the state of front-panel Alarm
indicator.
Table 3-1. ALARM/STATUS Port Pin Assignments
Pin
Number Signal Description
1, 5, 9 GROUND Signal return, ground potential.
2, 3, 4 ALARMS OUT TTL
6, 7 ALARMS IN TTL
8 ________________ Do not use or ground.
ALARM/STATUS
RS232
ALARM/STATUS
1 2 3 4 5
6 7 8 9
Alarm Outputs