Grass Valley 2200 - Manual (Page 23)

2-9
Error Detection
Protocol Errors
Errors can occur on the Protocol level itself; that is, the message may be received
okay, but may not actually be executed due to problems with content or context.
The only error that will be reported to the Editor as a Protocol Error (01 40) occurs
if either the byte count or the command code fail the validation test when a
complete message is received.
All other protocol errors go unreported back to the Editor. The only response the
Editor receives to these messages is a Command Accepted message. The handler,
when it uncovers a problem, will simply throw the message away and the user
will see no change to the operation of the Switcher.
Some possible causes of unreported protocol errors are listed as follows:
Content Errors:
¥ Invalid effects address.
¥ Invalid data (register number, analog value, etc.)
Context Errors:
¥ Command is Òpanel-centricÓ and may only be executed when the Switcher
is in a specific state.