User's Manual

05-4819A01, Rev. 08 LCT 450 Installation/Operation Guide 25
Note 1:
Channel select decoding as follows: High = no connection; Low = Gnd. See
table below for radio channel selections.
Note 2:
Provide low impedance path to ground to key transmitter.
11 Audio Isolated Ground
12 No connection (NC)
13 No connection (NC)
14 Channel Select 2 (See Note 1)
15 No connection (NC)
16 RS-485/422 Isolated Ground
17 TX Audio input to radio
18 Channel Select Isolated Ground
19 Channel Select 0 (Note 1)
20 No connection (NC)
21 PTT Isolated Ground
22 No connection (NC)
23 Channel Select 1 (Note 1)
24 TXD+ (RS-485/422 digital). Input to radio.
25 TXD- (RS-485/422 digital) Input to radio.
Table 5. Channel Selection Table
Channel 3 Channel 2 Channel 1 Channel 0 Selected
High (future use) High High High 1
High (future use) High High Low 2
High (future use) High Low High 3
High (future use) High Low Low 4
High (future use) Low High High 5
High (future use) Low High Low 6
High (future use) Low Low High 7
High (future use) Low Low Low 8
Table 4. P1 Control Interface Pin Descriptions