Black Box ME760A-R2, User Manual

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CHAPTER 3: Standalone Installation
The terminal block holds five crimp-style contact positions for connecting the
Transmit (XMT) and Receive (RCV) telephone lines. The Transmit and Receive
pairs are not polarity-sensitive. Using a screwdriver to gently lever open the
contacts, connect the Transmit pair to the XMT terminals; for 2-wire operation,
this is all you need. For 4-wire operation, connect the Receive pair to the RCV
terminals, making sure that local XMT is connected to remote RCV and local RCV
is connected to remote XMT. If you are using shielded cable, there is also a fifth
terminal for optional ground connection (at one end only!).
For detailed information on the pinout of the DB25 connector, see Table 3-1
below and on the next page.
Table 3-1. DB25 Pinout and Interface-Signal List
CCITT EIA DTE SIGNAL
V.24 RS-232-C PIN NAME DESCRIPTION
101 AA 1 Protective Chassis ground. Can be isolated from
Ground Signal Ground (refer to GND Strap in
Table 3-2).
102 AB 7 Signal Ground Common signal; DC-power-supply ground.
N/A N/A 9 +8 volts 8 VDC
10 –8 volts Output –8 VDC
103 BA 2 Transmitted Serial digital data received from (sent by) the
Data local DTE. See the Note on the next page.
104 BB 3 Received Serial digital data sent to (received by) the
Data local DTE. See the Note on the next page.
105 CA 4 Request to Local DTE sends a “high” (positive) level to
Send the LDM-MR19.2 when it wants to send data.
106 CB 5 Clear to Send After receiving a Request to Send from the
local DTE, the LDM-MR19.2 waits for a
user-selectable period, then sends a “high”
(positive) level to the DTE to signal that it is
ready to receive data.
107 CC 6 Data Set Ready The LDM-MR19.2 always sends a “high”
(positive) level to the local DTE except when
the LDM-MR19.2 is in local or remote digital
loopback.