Omega A2400 OC and CC Command Formats, Implied CC Command, Implied OC Command, Command Response

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: *