RS-232 Control, MX2426CV Contact, RS-232 Protocol

SWITCHERS

7.3 RS-232 CONTROL

A computer through RS-232 port can remotely control the MX2426CV. A terminal block connector is used to

make interconnection in the field easy. The RS-

232 commands are written using ASCII

character format. This makes it simple to program and control the MX2426CV.

The terminal block is labeled with the proper contact designations: Transmit (TX), Receive (RX), and Ground (GND). Always remember that the Transmit pin from the control system or computer must be connected to the Receive pin on the switcher control port; do not connect Transmit to Transmit or Receive to Receive.

Typically, a control system or computer will offer an RS-232 connection on a 9-pin D connector. The following are two typical cable pin-out designations for RS-232 connections. Always confirm the pin-outs for your system to insure proper wiring.

IBM PIN No.	MX2426CV Contact
3	RX
2	TX
7	GND
Connection IBM-PC 25-pin D to MX2426CV
Terminal Block

IBM PIN No.	MX2426CV Contact
2	TX
3	RX
5	GND

Connection IBM-PC 9-pin D to MX2426CV Terminal Block

Port setting preferences for the control system or computer being used to control the switcher should be set as follows:

BAUD Rate (Bits per second):	2400
Data Bits:	8
Parity:	None
Stop Bits	1

There is no software or hardware flow control implemented. The RS-232 input has a 6- character buffer and will not execute additional commands until the previous command is fully processed.

7.4 RS-232 PROTOCOL:

Standard RS-232 is used to control the switcher. Control can be accomplished either through a computer or through a control system.

RS-232 Protocol:

[AOFF] All channels off. Turns all monitor outputs off. This command does not affect source selection.

[RSET] Resets the unit to the POWER ON condition. During POWER ON all monitors are turned OFF. This is done to preclude accidental monitor connection during the power glitch.

[FSET] This command initializes the unit to the factory condition. All memories are reset. Do not use this command unless it is absolutely necessary.

[INP0] Turns all input sources to the OFF position. After executing this command input 1 and input 2 are disconnected from the outputs.

[INP1] Select input 1. This is the Plaintiff side.

[INP2] Select input 2. This is the Defendant side.