Wood and Douglas 1335, Operating Instructions Manual

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1892 1335 - Orion Radio Modem Operating Instructions - v2.9 / Aug 2009
GENERAL PARAMETER CONFIGURATION
Figure 22 - General Parameters tab
Factory-set Parameters
These parameters are to mainly do with the radio module used, and are set up in the factory.
They require the Level 2 password to unlock them before they can be adjusted.
Transmitter key-up time: This time in ms is allowed to elapse before any data is sent, to
ensure that the radio is ready. The value depends on the particular radio fitted.
Squelch to start of preamble: During receive, the Orion allows this period in ms to elapse
after the squelch has operated before looking for a preamble. Typical values are 5 for the SX
series radios and 7 for G-Max.
No of preamble blocks: The number of preamble blocks which will be sent after the key-up
time. Too few will not allow the remote receiver to establish sync, too many will waste
transmission time. 3 or 4 are typical values.
AT Commands Guard Time: Sets the minimum time in ms required to elapse either side of
the ‘+++’ AT command string for it to be recognised as such. 15ms is a typical value. See
p.63 for details.
Sync Tolerance: Regular sync frames of known content are sent over the link. Sometimes
they are imperfect, but because of forward error correction this does not indicate that the data
is unusable. This value indicates the number of imperfections which can be tolerated, and is
usually set at 4.
User-set Parameters
These parameters can be set without the use of a password.
No. of retries before packet is lost: (Present for Mode U using TP (packet) over-air
protocol only): The number of times a packet is resent with no acknowledgement being