Extron Electronics System 4xi Series - Manual (Page 59)

Appendix A • RS-232 Programmer’s Guide
Extron • System 4 xi Switcher Series • User’s Manual A-8
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 4 xi .
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 4
xi
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 4 xi .
Here are the codes for the ERC character used by the System 4 xi :
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.)