Omega A2400 - Manual (Page 57)

Extended Addressing 9-5
All commands that are available with single-byte addressing may be
accessed with Extended Addressing, and vice-versa; the only exceptions
being the OC and CC commands, which can be used only with Extended
Addressing.
OC and CC Command Formats
Once an A2400 has been configured correctly in Extended Address mode,
the only commands necessary for normal operation are the Open Channel
(OC) and Close Channel (CC) commands. Since these commands are used
most often, there are several variations available, both implied and explicit,
which trade-off speed with data security.
Implied CC Command
In Extended Address mode, the A2400 is programmed to close the ‘data
gate’ each time it detects a ‘{‘ or ‘}’ character. This is to safeguard against
the possibility of two or more A2400’s being on at the same time, which could
result in data collisions. This is done automatically whether the A2400 is
addressed or not. No response is generated by an implied CC command.
Implied OC Command
Since the OC command is the most commonly used command in Extended
Address mode, it has been assigned to be the default command if only the
address is sent as a command:
Command: {01 ({01OC is implied)
Response: * (A2400 #01 data path is open)
Command: }01 (}01OC is implied)
Response: *01OC1D
With the implied OC and CC commands, different A2400 channels may be
opened and closed with a minimum of command overhead:
Command: {01
Response: *
This command opens the data channel of A2400 #01. At the same time, all
other A2400’s on the same system detect the ‘{‘ character and interpret it as
an implied Close Channel command. All other A2400’s will automatically be
set to Close Channel.
Command: {02
Response: *