User guide
RS-232 Control of Tx and Rx Units
When the FOX Tx/Rx AV is configured by RS-232 commands, some commands are processed
by the transmitter and others are processed by the receiver. The SIS commands do not
distinguish between the two units. The system routes the commands based on where they
are processed.
A system block diagram showing which functions are processed by the transmitter and
which are processed by the receiver is shown below:
Transmitter Receiver
Fiber Link 1
Fiber Link 2
(optional)
Process
Input conguration
Audio gain
Process
Color
Tint
Brightness
Contrast
Video mute
Output conguration
Daisy chain/
loop out mode
Audio mute
Audio output level
Figure 10. System Block Diagram
For full functionality, both fiber optic links must be enabled. If only link 1 is enabled, the
ability to configure the system through SIS commands is limited by the lack of return
communication from the receiver to the transmitter:
All configuration carried out using the transmitter is processed normally because only fiber
link 1 is required.
Queries from the transmitter about the status of receiver settings are not processed correctly
because fiber link 2 is required to carry the return signal.
The receiver cannot be used to configure the transmitter because fiber link 2 is required.
The lack of communication between the transmitter and the receiver can result in
mismatches in the value settings of the two units, which may cause confusion with control
systems or software applications. To avoid this, within four seconds of link 2 becoming
active, the receiver settings are automatically copied to the transmitter to ensure settings for
both units match.
NOTE: When the receiver settings are copied to the transmitter, existing transmitter
settings are overwritten and it may be necessary to update those values.
FOX Tx/Rx AV • Conguration 12