User's Manual

«ProductName» User Manual
7M303-1 Rev A2 Page 34
The control lines on the serial port are used for controlling the flow of data and the peripheral attached to the
port. The most signals provided for on RS-232 serial interfaces are shown in the following table:
Pin #
Name
Typical RS-232 Serial Signal Functions
3
TXD
Transmit data from the computer to the Peoplefinder II.
2
RXD
Receive Data from the Peoplefinder II to the computer.
7
RTS*
Request to send data. This is an output from the computer to the Peoplefinder
II. It indicates to the Peoplefinder II that it is ready to exchange data.
8
CTS*
Clear to send. This is a signal from the Peoplefinder II to the computer
indicating that it is OK to send data.
4
DTR*
Data Terminal Ready to the Peoplefinder II. This signal indicates to the
peripheral that the host is ready to receive data.
1
DCD*
Data Carrier Detect from the Peoplefinder II.
9
RI*
Not implemented.
6
DSR
Data Set Ready from the peripheral. Indicates the peripheral is ready.
5
GND
System Ground
*The hardware flow control signals, RTS, CTS, DTR, DSR, and DCD are active low. In other words, they are set to binary zero (0) to
assert them and binary one (1) to negate them. Over an RS-232 cable, they are again inverted because RS-232 specification calls for
negative logic. Negating RTS is a binary 1, which is a negative voltage on the RS-232 port.
9.4 Auxiliary/Alarm Connector
A 15 pin D-Sub female connector is located on the rear of the unit. This connector has digital inputs used for
triggering alarms. It also has contacts for two relay outputs. The digital inputs may be programmed to
automatically generate a page. The relay outputs may be switched on remotely via the radio or console.
Note that all digital alarm inputs have an internal 10K pull-up resistors connected. Alarms are activated by
pulling the input to ground. Open circuit or a TTL/CMOS high level is the inactive state. Do not pull these
inputs above 5V.
Auxiliary/Alarm I/O Connector Pin Out
Pin Number
Function
1
Alarm 8
2
Alarm 7
3
Alarm 6
4
Alarm 5
5
Alarm 4
6
Alarm 3
7
Alarm 2
8
Alarm 1
9
Relay 1 contact A
10
Relay 2 contact A
11
Relay 2 contact B
12
Relay 1 contact B
13
No connection
14
No connection
15
Ground