20
LDM-MR19.2
Table 3-1. DB25 Pinout and Interface-Signal List (continued)
CCITT
EIA
DTE
SIGNAL
V.24
RS-232-C
PIN
NAME
DESCRIPTION
109
CF
8
Receive Line
The LDM-MR19.2 always sends a “high”
Signal Detector
(positive) level to the local DTE except when
(Carrier Detect)
the LDM-MR19.2 detects carrier loss or is in
local or remote digital loopback.
113
DA
24
External Trans.
Synchronous data-rate-clock input received
Signal Element
from the local DTE. Governs the Transmitted
Timing
Data signal. See the Note below.
114
DB
15
Transmitter
Synchronous data-rate-clock output sent to
Signal Element
the local DTE. Governs the Transmitted Data
Timing
signal. See the Note below.
115
DD
17
Receiver Signal
Synchronous data-rate-clock output sent to
Element Timing
the local DTE. Governs the Received Data
signal. See the Note below.
142
25
Test Indicator
The LDM-MR19.2 sends a “high” (positive)
level to the local DTE during any test mode.
141
18
Loop 3
When it receives this control signal from the
Test Command
local DTE, the LDM-MR19.2 goes into Local
Analog Loopback.
140
21
Loop 2
When it receives this control signal from the
Test Command
local DTE, the LDM-MR19.2 forces the
remote modem into Remote Digital Loopback.
NOTE:
When the LDM-MR19.2 is operating synchronously, transitions of the Transmitted Data and
Received Data signals happen at the same time as positive-going (“rising edge”) transitions of the active
clock signal.
