Command Set
Command Descriptions
All the commands may be used with normal addressing or Extended Addressing unless otherwise noted. Commands that are exclusive to the Extended Address mode are noted near the right hand margin. For example:
Closed Channel (CC) | (Extended) |
Closed Channel (CC) | (Extended) |
The Close Channel (CC) command is an Extended Address Mode com- mand that is used to close the communications data channel in an A2400. A closed communications channel will prevent the flow of serial data present on the A2400’s
Command: {01CC
Response: *
Command: }01CC
Response: *01CC11
Digital Output (DO)
The DO command controls digital output (DO0/ARTS pin) on the module connector. The digital output allows the module to control an external circuit under host command. The DO command requires an argument of two hex characters.
The digital output is wired to the collector of a transistor in the module. The collector is connected to +5Vdc through a 5.6kΩ pull up resistor. If the digital output bit is set to ‘1’ the transistor is turned on and sinks current. Note that when the digital output bit is set to ‘1’ the electrical output is near 0 volts. If the digital output bit is set to ‘0’ the transistor is turned off and sinks no current. See Figure 2.1 for details.
Assume that you wish to turn the digital output bit on (sinking current). Set data bit 0 to ‘1’. Since the module has only one digital output, all the other bits are ‘don’t cares’. For example, this command will turn the output ‘on’:
