User's Manual

9XTend™ OEM RF Module - Product Manual v2.x6x
© 2010 Digi Internatonal, Inc. 34
RM (Ambient Power - All Channels) Command
<Diagnostics> The RM command is used to
examine and report power levels on all channels.
If no parameter is given, the channels are
scanned one time. If a parameter is given, the
channels are repeatedly scanned for that number
of seconds. The maximum power level seen for
each channel is reported (i.e. peak hold).
A graphical spectrum analyzer can be implemented by repeatedly sending the RM command (with
no arguments) and reading the resultant 50 power levels (this is easiest to do when CF = 1 or 2).
mBd 001- :0 hC:]0 = FC nehw[ tuptuo
elpmaS 
Ch 1: -103 dBm
...
Ch 49: -99 dBm
46:]1 = FC nehw[ tuptuo elpmaS 
67 
... 
63
001
:]2 = FC nehw[ tuptuo elpmaS 
-103 
… 
-99
RN (Delay Slots) Command
<Networking & Security> The RN command is
used to set/read the time delay that the transmit-
ting RF module inserts before attempting to
resend a packet. If the transmitting module fails
to receive an acknowledgement after sending a
packet, it inserts a random number of delay slots
(ranging from 0 to (RN minus 1)) before attempt-
ing to resend the packet. Each delay slot is 5
msec (when BR=1) and 54 msec (when BR=0).
If two modules attempt to transmit at the same
time, the random time delay after packet failure allows only one module to tr
ansmit the packet
successfully; while the other module waits until the channel available for RF transmission.
RN Command is only applicable if retries have been enabled [RR (Retries) Command] or if forced
delays will be inserted into a transmission [TT (Streaming Limit) Command].
RO (Packetization Timeout) Command
<Serial Interfacing> The RO command is used to
set/read the Packetization Timeout setting. RF
transmission begins when data is in the DI buffer
and either of the following criteria are met:
 RO character times of silence on the UART
receive lines (after receiving at least 1 byte)
 RB characters have been received by the
UART
RB and RO criteria only apply to the first packet of
a multi-packet transmission. If data remains in
the DI Buffer (UART receive) after the first packet, transmiss
ions will continue in a streaming
manner until there is no data left in the DI Buffer.
When RO is the transmission-beginning criteria: The actual time between the reception of
the last character from the UART and the beginning of RF transmission will be at least 800 μsec
longer than the actual RO time to allow for transmission setup. Additionally, it is subject to 100-
200 μsec of additional uncertainty, which could be significant for small values of RO at high UART
bit rates.
AT Command: ATRM
Para
meter Range: no parameter - 0x7D0)
Number of bytes returned: 2
Related Commands: RC (Ambient Power -
Single channel)
AT Command: ATRN
Binary Command: 0x19 (25 decimal)
Parameter Range:0 - 0xFF [38 ms slots]
Default Parameter Value: 0
(no delay slots inserted)
Number of bytes returned: 1
Related Commands: RR (Retries), TT
(Streaming Limit)
AT Command: ATRO
Binary Command: 0x21 (33 decimal)
Parameter Range:0 - 0xFFFF
[ x UART character times ]
Default Parameter Value: 3
Number of bytes returned: 2
Related Commands: RB (Packetization
Threshold)