Specifications

724-746-5500 | blackbox.com
Page 14
Black Box
9. Insert one captive screw through a saddle washer, then insert the entire piece
through the hole in the DB-25 end of the case. Snap that side of the case
closed. Repeat the process for the other side. This completes cable installation.
3.2 CONNECTION TO THE RS-232 INTERFACE
Once you have connected the twisted pair wires correctly, simply plug the ME670A
directly into the DB-25 port of the RS-232 device. After doing so, remember to insert
and tighten the two captive connector screws.
Connection to a “DTE” Device
The ME670A is wired as a DCE, and therefore “wants” to plug into a DTE such as a
terminal, PC or host. Because the ME670A is interface powered, a direct connection
to the RS-232 DTE port is most desirable. If you must use a cable to connect the
ME670A to the DTE port, make sure it is a straight through cable of the shortest possi
-
ble length—we recommend 6 feet or less.
Connection to a “DCE” Device
Since the ME670A is wired as a DCE, you cannot connect it directly to another DCE
such as a modem, multiplexer or printer. If you need to connect the ME670A to
another DCE device, you must use a null modem cable wired according to diagram
below. We recommend a cable of the shortest possible length, preferably 6 feet or
less.
Note When connected to another DCE deice, the ME670A should be configured for
“external clock” (see “Switch Set SW1” on page 6)
Table 11: DCE Device Connection
Connection to ME670A
DB-25 Pin No.
Connection to DCE Device
DB-25 Pin No.
1 1
2 3
3 2
4 8
8 4
6 20
20 6
17 24
24 17
7 7