The Current-Loop Interface; Testing For Other Active Devices On The Current Loop; Led Test - Black Box 232/CL-E Manual

4. The Current-Loop Interface

4.1 Testing for Other Active Devices
on the Current Loop
You must test for an active device on
the current loop if you plan to have the
CL050 supply loop current.
WARNING!
Only one device on the
current loop may be active.
If more than one device is
active at the same time,
each device
permanently damaged.
There are two tests that you can run.
Either is sufficient.
Figure 4-1. Wiring configuration for a 4-wire current loop LED test.
Figure 4-2. Wiring configuration for a 2-wire current loop LED test.
RS-232 ↔ CURRENT LOOP INTERFACE CONVERTER
will be
R+
T+
R-
T-
T+
R+
T-
R-
T+
+
-
R-
4.1.1 LED T
EST
(1) Unplug the CL050 from the AC
outlet.
(2) Set the SWA switch to full duplex,
passive.
(3) Attach the T- of the 4-wire current
loop device (or "-" in a 2-wire current
loop) to R- of the CL050A.
(4) Attach the T+ of the 4-wire current
loop device (or "+" in a 2-wire current
loop) to R+ of the CL050A. See Figure
4-1 (4-wire current loop) or Figure 4-2
(2-wire current loop).
(5) Plug the CL050 into the AC outlet.
T+
T-
R+
R-
T+
T-
R+
R-
CL050A
CL050A
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