User's Manual

CDR-915L OEM DATA RADIO MODULE
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Revision M INTEGRATOR’S GUIDE
9
data. While reducing throughput, this feature also handles missed
transmissions as well as performs path management, allowing full duplex
communications.
The numeric value populated in the Retries field specifies the number of
attempts the radio will make in trying to resend unacknowledged packets.
The value in the Timeout field determines how long the radio will wait for the
acknowledgement before resending. (See Hardware Timing for more
information)
Number of Repeaters
The range of the CDR-915L may be extended by using repeaters. Repeater
modules receive data packets on one group code and retransmit the packet
on another group code. For example, a repeater configured with group
codes 3 and 4 will translate the following packets and retransmit them as
follows:
• A packet received with a destination group code of 3 will be received
and retransmitted with a destination group of 4.
• A packet received with a destination group code of 4 will be received
and retransmitted with a destination group of 3.
This method of group code translation guarantees that data is transferred
through the repeater and not directly between radios.
When the CDR-915L is in Ack-Back™ mode and there are repeaters in the
system, the amount of time needed to receive packet acknowledgements
increases. By specifying the number of repeaters in the Configuration
program, this delay is calculated and the radio is updated correctly. Always
populate this field with the maximum number of chained repeaters in the
system.