APCS Signal Isolator 4-20mA

The SI231 is a loop powered transmitter that combines signal isolation and conversion in one compact package. The SI231 is ideal for in field enclosures or as a space saver in larger control cabinets. The base unit features link select-ability for standard process inputs. No special tools or components are required for range changing in the field. Reverse or direct action mode is easily changed by solder pads on the base board. Standard output is 4-20 mA with a wide supply range of 7.5 - 40 Volt DC. This enables the SI231 to be used in 12 Volt battery supply in automotive applications. Other factory set output configurations are 10-50 mA loop powered and 0-10 mA, 0-20 mA or voltage output in 3-wire connection. Reference for 3-wire connection is the negative supply. Double surge protection is standard with all Series 200 loop powered transmitters to prevent failure due to spikes induced by DC switched inductive loads. Final calibration is trimmed using the front accessible zero and span 15-turn trim adjustments. A front mounted LED and a test socket verify module function and assist in calibration checks without disconnection of output wires.