Comtech EF Data HPOD, Installation And Operation Manual

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HPOD C-, X-, Ku-Band High-Power Outdoor Amplifier
Revision 9
Serial-Based Remote Product Management 5–3 MN/HPOD.IOM

Thermal Shutdown. The system indicates a temperature fault if the unit is

+95

C. This creates a summary fault and causes the
unit to mute itself, and switch to the backup unit if in a redundancy system. However, the 10V supply to the Field Effect
Transistors (FETs) will remain on until the unit reaches the thermal shutdown temperature of

100

C. For protection reasons, the
unit will shut down the 10V supply to the power transistors at temperatures

100

C.
5.2.5 Power Detector
The HPOD features a power detector to monitor the output power. It has a useful range of over 20 dB, referenced to the unit’s rated P1dB
point. To read its value, execute the “RMS” query (e.g., <1/RMS?<cr>). The test data supplied with each unit gives an indication of the
accuracy and flatness of the power monitor over the frequency band of operation.
5.2.6 Most Common Remote Queries

RMS (Retrieve Maintenance Status): Displays voltages, fan speeds, Heatsink temperature, output power monitor reading, etc.

RCS (Retrieve Configuration Status): Displays current attenuation, mute, amplifier, online, etc. status.

RAS (Retrieve Alarm Status): Displays current alarm or fault status.
5.3 Serial Remote-Control Introduction
Serial-based Remote Product Management of the HPOD is available via its J6 | COM1 port. This interface is either an EIA-485 multi-
drop bus (for the control of multiple devices) or an EIA-232 connection (for the control of a single device). The interface transmits data in
asynchronous serial form, using ASCII characters. This data consists of control and status information, transmitted in packets of variable
length in accordance with the structure and protocol explained later in this chapter.
5.3.1 EIA-485
For applications where multiple devices are to be monitored and controlled, full-duplex (4-wire plus ground) EIA-485 is preferred. Half-
duplex (2-wire plus ground) EIA-485 is possible but is not preferred. In full-duplex EIA-485 communication, there are two separate,
isolated, independent, differential-mode twisted pairs, each handling serial data in different directions.
It is assumed that a 'Controller' device (a PC or ASCII dumb terminal) transmits data in a broadcast mode via one of the pairs. Multiple
'Target' devices are connected to this pair, and all simultaneously receive data from the Controller. The Controller is the only device with a
line-driver connected to this pair – the Target devices have only line-receivers connected.