Specifications

260 Appendix E Display Cluster Protocol
Use a Telnet program to check the communication. Open the port specified
above, then type “ping” and press Return. WATCHOUT will respond with a
Ready message, stating its version number and some other details.
Serial Control To control a WATCHOUT display cluster through a serial port, connect the
controlling device to a serial port of one of the WATCHOUT display
computers. The computer you connect to becomes the master of the cluster, and
will automatically control the other cluster members, as specified by the presen-
tation loaded using the “load” command.
No serial port is open by default. Use the serialPort command to open a serial
port. Put this command into a text file, and use the file-based control feature to
perform the serialPort command (see “File-based Control” on page 257).
COMMANDS AND RESPONSES WATCHOUT uses a simple text format for its commands. Some commands
may return a reply, error message or other kind of response to the controller.
Such responses are also sent as text.
Authentication Before you can give any command (with the exception of the “ping”
command), you must specify the authentication level. To control WATCHOUT,
you need authentication level 1:
authenticate 1
WATCHOUT responds with a Ready message. You can now send other
commands.
Command Format Each command is sent as a string, terminated by a carriage return, line feed or
CR/LF pair. A command consists of a command name, sometimes followed by