Grass Valley NV9641A v.1.0 - Manual (Page 83)

73
GPIO
Chapter 6 provides information about the tally (GPIO) interface.
Topics
The Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
GPIO Configuration Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Configuring Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Configuring Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
The Interface
The tally interface includes 8 optically isolated inputs and 4 solid-state relay outputs (also opti-
cally isolated). Tally devices you connect to inputs can trigger events
— through the NV9641A —
in the router control system. The router control system can trigger events that — through the
relays in the NV9641A — switch your tally devices.
The DB25 connector, labeled “GPI Interface” at the rear of the NV9641A presents the tally
signals. There are 8 input signals and 4 pairs of output signals.
Fig. 6-1: GPI Interface
Input
The tally inputs expect contact closure to ground, through the ground pins on the connector, to
trigger a GPI input event.
Fig. 6-2: GPI Input
+ – + –
7 6 3 2
13
3
1
25 14
– +
2 1
– +
0 5 4
Inputs
1 0
Outputs
Ground
+ – + –
6 3
14
– +
2 1
– +
0
7 6 3 2 5 4 1 0
+5V
Optical
Isolation
C
E
+5V
Tally Input n
to internal bus
10K
Customer’s
Switch (or
Equivalent
Logic)