Operating instructions

1892 1335 - Orion Radio Modem Operating Instructions - v2.9 / Aug 2009 53
received, before regarding it as lost and a communications failure to exist. Equivalent to the
ATIPRT command.
Test Message Period: The time which is allowed to elapse in between transmissions of the
test string in response to the ATI3 command, in tens of milliseconds.
TX Priority: Don’t TX on busy channel: Normally, the Orion will not transmit if the squelch
indicates that there is already a transmission on frequency. However, where there is
interference, this box may be checked to transmit regardless.
Add RSSI and DQ at the end of each message: Check the box to append this information
to the end of every packet of user data sent.
TX Start Behaviour: Controls the behaviour of the Orion when it receives user serial data for
transmission on Serial Port A. For more detail on this, refer to page 24.
When set to Immediately, the transmission sequence is triggered as soon as a complete
byte is received in the transmit buffer.
When set to End of Message, the transmission sequence is triggered by a break in the User
Data input, assumed to be End of Message.
When set to Baud Rate Dependent, if Port A baud rate is similar to or higher than the over-
air rate, the first behaviour is followed (Immediate); if the Port A rate is lower than the over-air
rate, then the second behaviour is followed (End of Message).
The remaining two parameters only apply to Mode I Base and Outstations or Mode E
Outstations.
The Alert output: Can be set to respond to telemetry (I/O) alarms, housekeeping alarms (RF
link and PSU) or both, or switched off entirely. The time for which it latches on can be set from
0 to just over 10 minutes in 10ms increments. Alert output and permission to transmit an
alarm message are independently controlled.
The PSU Alarm boxes allow you to specify an upper and lower limit for PSU voltage
(expressed in volts rather than ADC units), and separate dwell times for each for which the
supply must exceed these limits to raise a an alarm. Entering a voltage of zero means no
alarm.