232CL2R4895 - pg. 1/1
B&B Electronics November 1995
Reversed Current Loop Converter
Model 232CL2R
Document No. 232CL2R4895
This B&B converter inputs RS-232 Transmit Data (2) and outputs 20 ma current loop signals, T+ and
T-. The device also inputs current loop signals, R+ and R-, and outputs RS-232 Receive Data (3). High
speed optical isolators couple and isolate the TD and RD.
The following information will help you
make your interconnection:
1.
Connectors. The 232CL2R uses a
female DB25S connector for the RS-
232 interface and a male DB25P
connector for the current loop interface.
2. Power for the Converter. The Model
232CL2R is designed to use +/- 12
Volts from pins 4, 5, 6, 8 and 20 to
power the RS-232 side of the unit. One
of these pins must be high and one
must be low for the unit to work. These
lines will not be necessary if you are
converting in one direction only, RS-
232 to current loop, and you do not
need to convert from current loop to
RS-232.
NOTE: When using an
external supply, the supply should
be connected only to specifically
labeled power inputs (power jack,
terminal block, etc.). Connecting an
external power supply to the
handshake lines may damage the
unit. Contact technical support for
more information on connecting an
external power supply to the
handshake lines.
3.
Current Loop Power. The unit will
operate with active or passive current
loop ports, and no power is required on
the current loop side of the converter if
you port is active. If your current loop
port is passive (does not have power),
an external power supply of about 12
Volts DC must be wired to pins 9 and
21. (See figure). These pins are
connected to resistors inside the
converter and are used to create the
20 ma. current source. Through-hole
resistors R11 and R12 allow you to
create a current loop other than 20 ma.
PDF 
ZIP