Axis Communications 250S user manual Appendix E - Unit Connections, The D-Sub Connector

46 Unit Connections AXIS 250S User’s Manual

Appendix E - Unit Connections

The D-Sub Connector

The AXIS 250S provides one 9-pin D-sub connector, providing the physical interface for an RS-232 port, used for connecting accessory equipment; such as stand-alone Pan/Tilt devices for the remote positioning of connected video cameras.

A diagram of the RS-232 connector, complete with pin assignment table, is shown below.

Pin Function

1CD

2- RXD

3	- TXD
4	DTR	1	2	3	4	5
5	GND		6	7	8	9
6	DSR
7	RTS

8CTS

9RI

The I/O Terminal Blocks

The two 4-pin I/O Terminal Blocks, A and B, are located on the rear panel and provide the interface to: a single transistor output, four digital inputs, an RS-485 interface and GND.

This section describes the pinout, interface support and the control and monitoring functions provided by the terminal blocks.

Note that the wiring for the pins on incoming plug connectors is not identical, but instead on opposite sides in relation to each other. Check the rear panel before wiring.

Connector Pinout - Terminal Blocks A & B

Pin	Function	Description
A1	GND
A2	Digital Input 1	To activate, connect to GND.
A3	Digital Input 2	To activate, connect to GND.
A4	Digital output	With a maximum load of 100mA and maximum voltage of 24V DC, this
		output has an open-collector NPN transistor with the emitter connected
		to pin 1. If it is to be used with an external relay, a diode must be con-
		nected in parallel with the load for protection against any voltage tran-
		sients.
B1	Digital Input 3	To activate, connect to GND
B2	Digital Input 4	To activate, connect to GND
B3	RS485A	RS-485/422 - A (non-inverting). A half-duplex RS-485/422 interface for
		controlling auxiliary equipment.
B4	RS485B	RS-485/422 - B (inverting)