User's Manual

MHPTV TX User Manual
MHPTV-USR-DOC-V3.0, 10/18/2019 Page 59 of 148
after BPF feedback signals are used by the Exciter to provide automatic Linear and
Non-Linear pre-correction of the forward path signal.
Additional feedback signals are provided to the Control module, which monitors
these samples to implement protective protocols including forward power reduction
and shutting down the TX in the event of high reflected power or other unsafe
operating conditions. System FWD and REV power samples are provided to the
Control module from the Directional Coupler located directly after the N-way power
combiner (for 2/3/4/5/6/8 PAs configuration). The Control module also receives
feedback samples from the System Reject Load(s) (for 2/3/4/5/6/8 PAs configuration),
enabling it to control the variable fan speed of the reject load(s).
The Control module is in constant communication with the Exciter and PA
modules via an RS-485 serial bus. Each module has a unique ID on the bus, and the
Control module is continually talking with the Exciter and PA modules to provide
monitoring and control capabilities via its front panel touchscreen and built-in web
user interfaces. Both the Control module and the Exciter provide RJ-45 Ethernet
connections through which the user may remotely monitor and control the TX via
their respective built-in web interfaces.