Comtech EF Data LTT1450G - Manual (Page 29)

LTT1450G Ku-Band Loop Test Translator Serial Interface Protocol
TM063 - Rev. 1 Page 5-1
Section 5 - Serial Interface Protocol
5.1 Introduction
This section describes the operation of the serial interface, the serial commands and the command
structure. The command set is described in three groups. The first group contains the user control
commands, the second group is the user status commands, and the third group covers the calibration
commands.
5.2 Command Structure
All commands can be communicated to the test translator over the full duplex asynchronous RS-232
serial port. The RS-232 interface hardware comes configured at 9600 baud, 1 start bit, 8 data bits, 1 stop
bit, no parity. Other baud rates are switch selectable. All command sequences are constructed from
ASCII character data. As such, it is possible to control the translator from a dumb terminal.
Command structure consists of the command header, the command, the command variables, and the
command delimiter. The command header prevents random character data from triggering an undesired
response. The command and command variable data will be described in detail below.
5.2.1 Status prompt
Upon power-up, the unit will send a status prompt of the form:
STATUS: BAND: {bb} ATT: {aa} {mode} {fault} >
Where bb represents the selected band; aa represents the selected attenuation; and {mode} contains the
current mode as follows:
LOC: Band and attenuation set by front panel switches
REM: Band and attenuation set by terminal
CAL: Unit in calibrate mode.
Any valid command entered from the terminal will put the unit in remote (REM:) mode. With the unit in
remote or calibrate (CAL:) mode, any change in the front panel switch settings will put the unit in local
(LOC:) mode and update the current status from the front panel. If a fault is detected {fault} it will
contain FLT, otherwise nothing will appear
.