Raveon RV-M7-UC-GX Quick Start Manual page 14

each TDMA time slot is 200mS long, and thus in 10 seconds, up to 50
M7 GX transponders may report position. These parameters are
programmable, and may be re-configured based upon the type of system
they are used in. Program the slot time with the SLTIME xxx command,
where xxx is in milliseconds.
For over-the-air rates of 4800 baud, Raveon Suggests using a SLTIME
of 200mS when using a repeater, or 100mS if there is no repeater in the
system.
A TDMA "Frame" time is the time it takes all units to transmit. This is
configured with the TDMATIME xx command. The factory default is 10
seconds, so every 10 seconds, each M7 GX is allocated a time-slot that
it may use to transmit position in. The TDMA frame must be set long
enough for all units to transmit. For example, if you have 50 M7s, and
use 200mS TDMA slots, then the TDMATIME should be set to 10
seconds.
The duration of a TDMA time slot is programmed into the M7 GX with the
SLOTTIME command. If SLOTTIME is set to 200 milliseconds (factory
default), then every 10 seconds, the M7 will have a 200mS window to
report its position in.
All TDMA frames are synchronized automatically in all M7 GX
Transponders to the top of the minute. Slot 0, frame 0 is at the top of
each minute.
8. Operation
Once power is applied to the M7 GX, the internal GPS will begin to try to
lock onto the GPS satellites.
The two LEDs on the front of the M7 will begin to alternately blink red
back-and-forth.
After 10 to 60 seconds, depending upon the satellite strength, the red
alternating blinking will stop. This indicates the internal GPS receiver is
locked onto GPS satellite signals, and has a position fix.
The M7 GX will only transmit if it has GPS lock. If the GPS antenna is
broke or obscured, the unit will not report position or status.
When it is locked to GPS, it will transmit its position and status at the
interval programmed into the TXRATE parameter.
Refer to the M7 GX Technical Manual for details on all of the events that
will trigger a transmission.
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M7 GX Quick Start Guide Raveon Technologies Corp.