Grass Valley 2200 - Manual (Page 20)

2-6
Section 2 Ð Editor Protocol
Command Code Byte
The command code is the third byte of the command/message block. Command
codes fall into two broad categories: read commands and write commands. Only
one command is allowed in any command/message block. Likewise, only one
response is embedded in any command/message block.
Read Commands
Read commands interrogate the status of the speciÞed operational parameter of
the switcher. When the editor issues a read command/message block, the
switcher responds by sending the current status of the requested operational
parameter(s) back to the editor. This status information is returned in the format of
the write command/message block. By echoing the write format, the editor can
later send responses to a read command to the switcher and cause execution of
that function.
Write Commands
Write commands are used by the editor to change operational parameter(s) or
initiate a function within the switcher.