Black Box ME375A-R2, User Manual

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ASYNC/SYNC 2-WIRE SHORT-HAUL MODEMS
ITU-TSS EIA Signal Name/ ITU-TSS Signal Name/ Description
(CCITT) RS-232 Abbreviation for V.35 Abbreviation for
V.24 Pin EIA RS-232 Pin(s) ITU-TSS V.35
Circuit (ME375) (ME375) (ME376) (ME376)
107 6 Data Set Ready (DSR) E Data Set Ready (DSR) If DIP Switch Position 7 is
set to DSR, the A/S2W
SHM holds this signal high
unless it is in digital
loopback or receives a
remote-loopback signal
from the remote unit.
If DIP Switch Position 7
is set to DTR, the A/S2W
SHM lets this signal follow
(reflect) the remote unit’s
DTR.
108.2 20 Data Terminal Ready H Data Terminal Ready The DTE raises this signal
(DTR) (DTR) when it is ready to transmit
or receive. If the remote
unit’s DIP Switch Position
7 is set to DTR, the remote
unit’s DSR will follow
(reflect) this signal.
109 8 Received Line Signal F Received Line Signal More commonly known as
Detector (RLSD) Detector (RLSD) Data Carrier Detect (DCD).
The A/S2W SHM holds
this signal high unless
RTS goes low or carrier is
lost.
113 24 Transmitter Signal U Serial Clock Transmit More commonly known as
Element Timing [DTE] Exetrnal A (SCTE A) External Clock (EXC). The
(TSETT) W Serial Clock Transmit DTE sends this data-rate
External B (SCTE B) clock signal to the A/S2W
SHM, which in turn passes
it to the remote unit. The
A/S2W SHM derives its
sync clock from this signal
only if its CLOCK jumper is
set to EXT. Positive clock
transitions correspond to
positive data transitions.