RS-232/Remote Control, cont’d, Error responses

RS-232/Remote Control, cont’d

The A/V switchers’ rear panel Remote connectors (Figure 4-1) can be connected to the serial port output of a host device, such as a computer or control system, to an Extron IR 20 Universal SYS 4/8/10/AV remote control, or to a remote contact closure device. Other than the IR 20, remote communications with the switcher are via Extron’s Simple Instruction Set, Extron’s Windows-based control program, or pin-programmed in the case of a contact closure device.

5	1	1	5
9	6	6	9
Female		Male

Figure 4-1 — Remote connector pinout

The RS-232 protocol of the rear panel RS-232/Remote connector is 9600 baud, 1 stop bit, no parity, and no flow control. The connector has the following pin assignments:

Pin	RS-232	Contact closure	Function
1	—	In#1	Input #1
2
2	TX	—	Transmit data (-)
3
3	RX	—	Receive data (+)

4	—	In#2	Input #2
5	Gnd	Gnd	Signal ground
6	—	In#3	Input #3
7	—	In#4	Input #4
8	—
8	—	In#5	Input #5
9	—	In#6	Input #6

Simple Instruction Set Control

Host-to-interface communications

SIS commands consist of one or more characters per field. No special characters are required to begin or end a command character sequence. When a command is valid, the switcher executes the command and sends a response to the host device. All responses from the switcher to the host end 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 or error condition, occurs, the switcher responds by sending a message to the host. The switcher-initiated messages are listed below:

The switcher issues the copyright message and input selected message when it first powers on. Vx.xx is the firmware version number. Cn identifies the currently selected input, where n is the input number (input 1 is the power-up default in normal mode). The switcher also sends the Cn message whenever the selected input is changed using the front panel buttons.

Reconfig

The switcher initiates this message when there is a change in an audio model’s audio gain setting.

Error responses

When the switcher receives a valid SIS command, it executes the command and sends a response to the host device. If the switcher is unable to execute the command because the command is invalid or it contains invalid parameters, the switcher returns an error response to the host. The error response codes are:

E01 - Invalid input channel number (out of range)