54
SD Series Technical Manual
MDS 05-4846A01, Rev. H
•
Push-To-Talk Delay (ms)
—Allows programming a brief time delay
after a keying event, which must expire before the radio is
allowed to transmit. The allowable range is 0 to 255 ms, with the
default being
0
.
•
Clear-To-Send Delay (ms)
—Allows programming a brief time delay
between when an RTS (ready-to-send) signal is received and
when the CTS (clear-to-send) signal is returned. The allowable
range is 0 to 255 ms, and the default is
0
.
•
Automatic Freq. Correction
—Automatic Frequency Correction
(AFC), is used to counteract the slight RF frequency drift that
may occur over time or through wide swings of ambient temper-
ature.
•
Switched Carrier (B Modems)
—In some networks, the Master unit is
not keyed continuously (Ckeyed), and transmits only when it has
data to send to Remotes. This is known as Switched Carrier oper-
ation. The Switched Carrier setting is only for use on radio
modems with “B” suffixes (for compatibility with MDS x710
radios). In such networks, the Remote radios should have the
Switched Carrier
setting turned
ON
. The default setting is
OFF
which
assumes B-modem operation with a continuously keyed Master.
Ckey Operation only applies to Master units operating in
full-duplex mode only. Master units in B-modem networks will
have SWC set to
ON
regardless of Ckey being on or off.
•
RX Signal Attenuation
—This setting is intended for use in strong sig-
nal environments (typically -70 dBm or stronger). When enabled
the radio will tolerate very strong signals of -20 dBm or stronger.
Note that RX Signal Attenuation will reduce sensitivity by a few
dB, so it should be disabled for maximum sensitivity when work-
ing with extremely weak signals.
•
Force DCD to Asserted
—Some systems require a constant Data Car-
rier Detect (DCD) signal. This setting allows the radio to be con-
figured to provide a DCD signal without the need for special
cabling.
•
Data Key Hold Time-out
(chars)
— For networks with the demand for a
higher modem speed then the baud rate, this parameter can be
adjusted from 1 to 10 characters. This parameter gives the overall
network better performance by preventing frequent key-up and
key-down sequences between characters. This only applies to net-
works with all-SDx radios. The default setting is
2
characters.