Installation guide

166 Programming Commands
7.7 Host Commands - Alphabetical Listing
" <n " Miscellaneous Command
ACTION: This command activates/deactivates a controller from accepting com-
mands from a host computer.
COMMAND SYNTAX: <n or <n cr
<n?
<0 or <0 cr
REMARKS: In order to daisy chain multiple controllers to communicate with a single
host, each controller must be given a unique identification number. The
Unit ID # selector switch defines the identification number of the con-
trol. This switch is interrogated on power turn on only. The factory set-
ting is device 1.
Each Controller must be given a unique identification (1-9)
before the system is wired.
In order to accept commands from a host device, a Control must be set
to the active mode. To do this, the host must send the device attention
command (<) followed by the device identification followed by a car-
riage return, line feed or non-numeric character. If n matches the con-
troller id number, that unit becomes the active controller.
If the host requires an acknowledgement of the active controller the <n?
command is transmitted by the host and if the device exists it will re-
spond with its id number.
If all controllers are to be placed in the listen mode the host issues a
<0cr command. No data can be transferred from the Control to the
host in this mode. However, all other commands will be honored by the
controllers.
" ? " Miscellaneous Command
ACTION: The ? key (or ? character code, ASCII 63, sent via a serial port) re-
quests the space remaining in the Host Receiver buffer.
COMMAND SYNTAX: ?
REMARKS: The controller receiver buffer is 255 characters long.