Extron electronic TPX 88 manual Programmer’ser’sGuide,Guidecont’d, Host-to-Switcher Instructions

Programmer’ser’sGuide,Guidecont’d

The switcher’s rear panel 3.5 mm, 5-pole captive screw connector (figure 4-1) can be connected to the RS-232 or RS-422 serial port output of a host device such as a computer running the HyperTerminal utility, an RS-232 capable PDA, or a control system. This connection makes software control of the switcher possible.

GND	TX- TX+ RX- RX+	Pin	RS-232			Function		RS-422	Function
		Gnd		Gnd		Signal ground		Gnd	Signal ground
		TX-			—	Not used		TX-	Transmit data (-)
		TX+		TX+		Transmit data		TX+	Transmit data (+)
		RX-			—	Not used		RX-	Receive data (-)
		RX+		RX+		Receive data		RX+	Receive data (+)
				RS-232					RS-232
							RS-422	RS-232
							Settings	Settings
				RS-422					RS-422

Figure 4-1 — Remote connector pin arrangement

The TPX switcher can communicate using either the RS-232 or RS-422 serial communication protocol. The protocol is DIP-switch selectable. See chapter 2, Installation, to configure the DIP switches.

The protocol is 9600 baud, 8-bit, 1 stop bit, no parity, and no flow control.

Host-to-Switcher Instructions

The switcher accepts SIS (Simple Instruction Set) commands through the RS-232/RS-422 port. SIS commands consist of one or more characters per command field. They do not require any special characters to begin or end the command character sequence. Each switcher response to an SIS command ends with a carriage return and a line feed (CR/LF = ), which signals the end of the response character string. A string is one or more characters.

Switcher-Initiated Messages

When a local event such as a front panel operation occurs, the switcher responds by sending a message to the host. The switcher-initiated messages are listed below (underlined).

(c)Copyright 2003, Extron Electronics, TPX 88, Vx.xx

The switcher initiates the copyright message when it is first powered on. Vx.xx is the firmware version number.

Qik

The switcher initiates the Qik message when a front panel switching operation has occurred.

Rprnn

The switcher initiates the Rpr message when a memory preset has been recalled from the front panel. “nn” is the preset number.

Sprnn

The switcher initiates the Spr message when a memory preset has been saved from the front panel. “nn” is the preset number.

Innn Audxx

The switcher initiates the Aud message when a front panel audio level operation has occurred. “nn” is the input number and “xx” is the dB level.

4-2 TPX 88 Matrix Switchers • Programmer’s Guide