Appendix A • RS-232 Programmer’s Guide

Advanced Instruction Set

The Advanced Instruction Set uses commands that are longer than one character because they are more complex than the Simple Instructions described earlier. Advanced Instructions can be used in programs that may be stored and executed as needed.

The system sees the RS-232 information in two general categories:

If bit 7 = 0 (00h - 7Fh), this byte is an instruction.

If bit 7=1 (80h - FFh), it is considered to be data, or information.

However, only certain codes are used by the System 4xi.

The components of an Advanced Instruction are:

Escape Code (ESC) - to indicate the start of command Command Code - to tell the switcher what to do

Subcom - Data (if required) – as many bytes as required for parameters to supplement the Command Code

End Of Transmission (EOT) - to indicate the end of this command

Switcher response to the command:

Escape Code (ESC) - to indicate the start of a response

Command Code - repeated to identify what the response is for

Error Code (ERC) - to indicate no error, or what type of error

Data (if required) - to give the host what was requested

End Of Transmission (EOT) - to indicate the end of the response

The command protocol is as follows:

ESC, Command1, Subcommand1.1, Subcommand1.2, etc... EOT

Advanced Instruction List

The commands listed here are Advanced Instructions, however, they can be intermixed with commands from the Simple Instruction Set.

Command

Hex

Description

 

 

 

 

 

CMD4

34h

Select input channels (audio and video)

 

CMD5

35h

Request system status

 

CMD6

36h

Adjust settings (incremental)

 

CMD8

38h

Set up System 4xi for slave configuration

 

CMD9

39h

Configure an input channel

 

CMD10

3Ah

Request input channel configuration

 

CMD11

3Bh

Configure system

 

CMD12

3Ch

Request system configuration

 

(These are command characters, because they are in the range of 00h - 7Fh.)

Error Codes (ERC)

An ERC character is included with each response from the System 4xi. Here are the codes for the ERC character used by the System 4xi:

80h = No error

81h = Invalid channel

82h = Command not recognized (illegal command)

84h = Projector communication error

85h = Switcher is Off, cannot execute the command 8Ah = Invalid command

8Dh = Invalid parameter value

(These are data characters, because they are in the range of 80h - FFh.)

Extron • System 4xi Switcher Series • User’s Manual

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Extron electronic 4LQXI Advanced Instruction Set, Advanced Instruction List, Error Codes ERC, Command Hex Description