Datasheet W181A-P502 · 4-20 mA to two relays with adjustable limits, with OLED display

W181 module in compact DIN rail enclosure, front three-quarter view: OLED display, three push buttons, DIP switch, USB-C port and screw terminals

The W181A-P502 reads a 4-20 mA signal and switches two relays, each with its own limit and hysteresis. For each relay you choose whether it switches above or below its limit; one module thus provides a low and a high alarm, or a pump that switches on and off at two levels. The limits are set on the OLED display as a percentage or in the unit of the sensor. A broken wire (less than 4 mA) can be detected and can switch a relay.

Price on request. Supplied in series, from 10 units per item. Not in stock? Then we build your series. One or a few units only as a trial, for a company with a series in sight.

Specifications

Supply	24 V DC (±15 %)
Input	4-20 mA (also 0-20 mA)
Output	Two relay contacts
Isolation	Not galvanically isolated
Setup	OLED display with UP, DOWN and OK buttons; DIP switch for basic choices
Switching point	Per relay limit, hysteresis and direction (above or below) adjustable; alarm on broken wire
USB	USB-C for software updates and reading the status
Wi-Fi	Built-in hotspot for software updates
Mounting	DIN rail, compact enclosure
Internally fitted with	PR181s09

Setup

Connect the supply, the 4-20 mA source and the relay contacts according to the wiring diagram supplied with the module.
On the display, set the limit, hysteresis and direction for each relay.
Choose whether a relay switches on a broken wire and store the settings.