Ext Ptt; Rxd Hi; Txd Low; Txd Hi - Vertex Standard VXR-7000 Service Manual

Pin 12: EXT PTT
This input is internally pulled up to 5 VDC. When
pulled low by an external device, it keys the repeater
transmitter while the repeater is operating in the
"BASE" mode. Avoid voltage in excess of 5 V on this
pin, or internal damage to the microprocessor on the
repeater CNTL Unit may result.
Pin 13: GND
Chassis ground for all logic levels and power supply
return.
Pin 14: GND
Chassis ground for all logic levels and power supply
return.
Pin 15: N.C. (No connection.)
Pin 16, 17, 18, & 19: REMOTE CH DATA
[Logic Inputs D3, D2, D1, and D0] (Active Low)
These inputs are internally pulled up to 5-V DC. When
pulled low by an external device, they select one of the
16 pre-programmed repeater operating channels. The
logic truth table below shows the combinations for se-
lecting all 16 channels.
In the truth table, "1" represents no connection, and
"0" represents a ground connection on the pin.
The channel selection logic is not inhibited while the
transmitter is keyed: the repeater will change frequency
when instructed, even while transmitting.
Avoid voltage in excess of 5 V on these pins or inter-
nal damage to the microprocessor on the repeater CNTL
Unit may result.
Pin 16
Channel
( D3 )
1 1
2 1
3 1
4 1
5 1
6 1
7 1
8 1
9 0
10 0
11 0
12 0
13 0
14 0
15 0
16 0
Pin 17 Pin 18 Pin 19
( D2 ) ( D1 ) ( D0 )
1 1 1
1 1 0
1 0 1
1 0 0
0 1 1
0 1 0
0 0 1
0 0 0
1 1 1
1 1 0
1 0 1
1 0 0
0 1 1
0 1 0
0 0 1
0 0 0
Operating Manual Reprint
Pin 20: GND
Chassis ground for all logic levels and power supply
return.
Pin 21: A-OUTPUT [Logic Output] (Active Low)
This open collector logic output is pulled low when
the front panel's ACCESSORY key is turned on. It
can sink approx. 10 mA when active.
Pin 22: RXD LOW
[Digital Output for DATA Communications]
(300 ~ 3,000 Hz)
This pin is an output for low speed receiving data sig-
nals, with the data being extracted after the de-empha-
sis and low pass filter stages.
Pin 23: RXD HI
[Digital Output for DATA Communications]
This pin is an output for high speed receiving data sig-
nals, with the data being extracted immediately after
the discriminator prior to any de-emphasis).
Pin 24: TXD LOW
[Digital Input for DATA Communications]
(300 ~ 3,000 Hz)
This pin is intended to be used as a low speed digital
data signal input to the repeater. This digital data sig-
nal is injected before transmitter pre-emphasis and lim-
iting stage, so excess signal input levels are clipped.
Pin 25: TXD HI
[Digital Input for the DATA Communications]
This pin is intended to be used as a high speed digital
data signal input to the repeater. This digital data sig-
nal is injected after transmitter splatter filter stage.
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