Gefen TOOLBOX GTB-MINI-PACS, User Manual

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RS-232 / TELNET COMMANDS
Bridging Settings
RS-232 Feedback and Delimiters
One advantage of RS-232 serial control over IR control is that RS-232 offers
2-way communications between a device and the control system. This allows
the controlled device to provide feedback to confi rm that its operating state
matches the control system’s assumptions. For example, when the control
system sends Volume Up or Volume Down commands to the device, feedback
allows the device to send its current volume setting back to the control system.
This prevents the device from getting out of sync with the controller, especially if
the user changes the volume manually on the device, or with an IR remote.
It also allows the control system to accurately track the current power state, input
settings, and other important data.
However, in some cases, the controlled device might send more data than the
control system can easily decode (parse) and act on, or may send random data
that the control system does not require or understand.
Delimiters are supported by the Mini PACS to control feedback data sent from a
controlled device to the control system. Delimiters allow the Mini PACS to ignore,
or to collect and store the data, until a recognizable command arrives, and then
send that complete command to the control system.
If a “Start Delimiter” is specifi ed, the Mini PACS will ignore feedback from the
controlled device until the specifi ed string of characters arrives. The string may
be one, two, or three specifi ed hex characters (bytes) from “00” – “ff” each. Each
character can be specifi ed, or “**”may be used if any character can appear in the
string (a “wild card”).
When the “Start Delimiter” is detected, the Mini PACS will begin to collect the
data string that follows in an internal buffer memory until either:
1. An “End Delimiter” has been specifi ed and is detected,
2. The specifi ed time-out is exceeded, or
3. A specifi ed maximum number of bytes (up to 255) are collected
When any of these events occur, the data in the buffer is sent to the control
system over the IP connection.
The Start Delimiter, End Delimiter, Force Send Timeout, and Force Send Byte
Count can all be specifi ed in the Web Interface, or through Telnet commands.
The End Delimiter has the same parameters as the Start Delimiter- zero, one,
two, or three characters or “wild cards”.
Note that the delimiters only affect feedback from a controlled device- they have
no effect on commands sent from the Mini PACS to the device.