Half-Duplex Operation - Black Box CL512A-F User Manual

MODULAR CURRENT LOOP ADAPTER
3.2.2 H -D
ALF UPLEX
Table 3-2. Pinouts for Half-Duplex Current-Loop Connections
*Half-duplex operation is not recommended for RJ-11 connections due to the
difficulty involved in crossing Jumpers 2 and 3.
Typical half-duplex applications for the adapter are shown in Figures 3-4 and 3-5.
In Figure 3-4, the unit is connected to a DTE device. In Figure 3-5, the unit is
connected to a DCE device.
When connected to a DTE device, the adapter does not output pins 5
(CTS), 6 (DSR), or 8 (CD). If your computer needs these pins before it
can send data, you must use a short cable with the proper pin
configuration between the computer and the unit. This entails looping
pin 4 (RTS) or any other signal at +12 volts to pins 5, 6, and 8 on the side
connected to the computer.
When connected to a DCE device, the adapter does not output pins 4
(RTS) or 20 (DTR). If your modem needs these pins before it can send
data, you must use a short cable with the proper pin configuration
between the modem and the unit. This involves looping pin 8 (CD) or
any other signal on the interface that is at +12V to pins 4 and 20 on the
side connected to the modem.
10
O
PERATION
RJ-11 Modular Pinnings*
Jumper 1 to 2
Terminal Block Pinnings
Jumper 2 to 3
3 = + Loop
4 = - Loop
1 = + Loop
4 = - Loop
NOTE