VXR-9000 FM R
EPEATER
O
PERATING
M
ANUAL
Pin 10
,
13
,
15
,
16
,
17
,
18
,
19
,
21
:
P
ROGRAMMABLE
I/O “1” ~ ”8”
The
VXR-9000
provides eight ports
(PIO) that can be programmed for vari-
ous input or output signals, or for con-
trol functions. Each port may be pro-
grammed as to its function, its status (in-
put or output), and its logic (for output
ports only).
Pin 11
: NSQ DET
This is an open-collector, active-low output capable of
sinking about 10 mA. It indicates that the receiver
squelch is open. If the squelch control is properly set,
this indicates a carrier on the receiver channel.
Pin 12
: EXT PTT
This input is internally pulled up to 5 VDC. When pulled
low by an external device, it keys the repeater transmit-
ter while the repeater is operating in the “
Remote
”
mode. Avoid voltage in excess of 5 V on this pin, or in-
ternal damage to the microprocessor on the repeater
CNTL Unit may result.
Pin 14
,
20
: GND
Chassis ground for all logic levels and power supply
return.
Pin 22
: RXD LOW
[
A
NALOG
O
UTPUT
FOR
DATA C
OMMUNICATIONS
]
(
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 HIGH
[
D
IGITAL
O
UTPUT
FOR
DATA C
OMMUNICATIONS
]
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
[
A
NALOG
I
NPUT
FOR
DATA C
OMMUNICATIONS
]
(
300 ~ 3,000 Hz
)
This pin is intended to be used as a low speed data sig-
nal input to the repeater. This digital data signal is in-
jected before the transmitter pre-emphasis and limiting
stages, so excess signal input levels are clipped.
Pin 25
: TXD HIGH
[
D
IGITAL
I
NPUT
FOR
THE
DATA C
OMMUNICATIONS
]
This pin is intended to be used as a high speed digital
data signal input to the repeater. This digital data signal
is injected after the transmitter splatter filter stage.
DB-25 C
ONNECTOR
P
ORT
8
Pin I/O Port
10
7
13
8
15
5
16
4
17
3
18
2
19
1
21
6
