GDR 66 Installation Manual
Page 4-7
190-00303-24
Revision A
4.4 Discrete I/O
4.4.1 Active Low Discrete Inputs
The GDR 66 provides 8 configurable discrete inputs conforming to:
Low: 0 VDC < Vin < 3.5 VDC, OR Rin < 375 ohms (active)
High: 8 VDC < Vin < 36 VDC, OR Rin > 100k ohm (inactive)
4.4.2 Key Event Out
The GDR 66 provides one output to signal when the GDR 66 is transmitting, regardless of what mode the
radio is in. KEY EVENT OUT* can be used as needed to decrease the sensitivity of other COM receivers
on the aircraft when the GDR 66 is transmitting. KEY EVENT OUT* is a non-configurable discrete
output conforming to:
Active: 0 VDC < Vout < 1.0 VDC with < 20 mA sink current; sink current must be externally
limited to 20 mA max.
Inactive: Open circuit, can be pulled up to an externally sourced Vout in the range 3.3 VDC < Vout
< 36 VDC; leakage current is typically <10 uA to ground.
Table 4-10 Discrete Inputs
Pin Name
Connector
Pin
I/O
DISCRETE IN* 1
P662
10
In
DISCRETE IN* 2
P662
11
In
DISCRETE IN* 3
P662
12
In
DISCRETE IN* 4
P662
13
In
DISCRETE IN* 5
P662
14
In
DISCRETE IN* 6
P662
15
In
DISCRETE IN* 7
P662
16
In
DISCRETE IN* 8
P662
17
In
Table 4-11 Key Event Out
Pin Name
Connector
Pin
I/O
KEY EVENT OUT*
P661
35
Out
DRAFT