Rugged Radios RM-50 - DCS Code Inversion; Reset Procedure

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R
ESET
P
ROCEDURE
M
ISCELLANEOUS
S
ETTINGS
DCS C
ODE
I
NVERSION
The DCS system was first introduced in the commercial LMR (Land Mobile Radio)
service, where it is now in widespread use. DCS is sometime referred to by its different
proprietary names, such as DPL® (Digital Private Line®, a registered trademark of Mo-
torola, Inc.).
DCS uses a codeword consisting of a 23-bit frame, transmitted (subaudible) at a data rate
of 134.4 bps (bit/sec). Occasionally, signal inversion can result in the complement of a
code to be sent or received. This prevents the receiver’s squelch from opening with DCS
enabled, as the decoded bit sequence would not match that selected for operation.
Typical situations that might cause inversion to occur are:

Connection of an external receiver preamplier.

Operating through a repeater.

Connection of an external linear amplier.
Note that code inversion does not mean that any of the above listed equipment is defec-
tive!
In certain amplier congurations, the output signal (phase) is inverted from the input.
Small signal or power ampliers having an odd number (1, 3, 5, etc.) of amplication
stagesmay result in inversion of a transmitted or received DCS code.
While under most circumstances this should not occur (amplifier designs and industry
standards take this into account), if you find that your receiver squelch does not open
when both you and the other station are using a common DCS code, you or the other sta-
tion (but not both) can try the following:
1. Press and hold in the [
BAND
(
SET
)] key for 1/2 second to enter the Set mode.
2. 2. Rotate the
DIAL
knob to select Menu #10 (
DCS.
N
/
R
).
3. 3. Press the [
BAND
(
SET
)] key momentarily, then
rotate the
DIAL
knob to select the following mode.
T/ R X N
: Encoder; Normal, Decoder; Normal
RX R
: Encoder; Normal, Decoder; Reverse (In-
verted)
TX R
: Encoder; Reverse (Inverted), Decoder; Normal
T/ R X R
: Encoder; Reverse (Inverted), Decoder; Reverse (Inverted)
4. Press the [
BAND
(
SET
)] key momentarily to save the new setting, then press and hold
in the [
BAND
(
SET
)] key for 1/2 second to exit to normal operation.
Remember to restore the default setting to “
T
/
RX N
” (Encoder; Normal, Decoder; Nor-
mal) when done.
In the event of erratic operation of the transceiver, it is possible that data on the micropro-
cessor may have become corrupted. While this is a highly unusual situation, the only path
ro recovery may involve resetting of the microprocessor. Here’s how to do this:
1. Turn the radio off.
2. Press and hold in the [
MHz
(
PRI
)] key while turning the radio on.
3. Rotate the
DIAL
knob to select the resetting menu:
F-1 SETRST
: Resets the Set (Menu) mode settings to their factory defaults.
F-2 HYPRST
: Clears the Hyper Memory settings to factory defaults.
F-3 MEMRST
: Clears the Regular Memory settings to factory defaults.
F-4 MB RST
: Clears the Memory Bank Assignment.
F-5 ALLRST
: Clears all memories and other settings to factory defaults.
4. Press and hold in the [
BAND
(
SET
)] key for 1/2 second to complete the reset proce-
dure, once you have made your selection in step 3.