4-20mA Analogue Channel Details

A 4-20mA "current loop" channel is available through any Wildeye cable types that contain the "A" code.

Example: WILD-M-R-NACS-NACS

4-20mA channels are designed to read analog signal outputs from pressure, level, environmental, process, industrial and other sensors and meters.

The Wildeye 4-20mA channel makes available a "Switched Power Output" power source to power a 2-wire 4-20mA "current loop" sensor, but it can also support 0-20mA signals, and signals coming from other 3-wire and 4-wire meters and sensors.

Select the appropriate accessory to attach to your meter or sensor.

For meters/sensors with "bare wire" leads, select the M12 Field Connect accessory to attach to the flying lead. Wildeye M12 "Field Connect" Wiring
For meters/sensors with terminal block connections, use the M12 Bare Wire cable accessory. Wildeye M12 "Bare Wire" Cable Wiring

For detail specifications on the Wildeye 4-20mA channel, jump to 4-20mA Channel Details

Wildeye M12 "Field Connect" Wiring

M12 Field Connects are available in 3 different sizes to suit the thickness of the cable coming from your meter/sensor:

ACC-CON-M12-5POS-M-3 - For meters/sensors with output cable thickness 2.5-3.5mm diameter
ACC-CON-M12-5POS-M-6 - For meters/sensors with output cable thickness 4-6mm diameter
ACC-CON-M12-5POS-M-8 - For meters/sensors with output cable thickness 6-8mm diameter

Wildeye M12 "Bare Wire" Cable Wiring

Order part ACC-CAB-M12-M-5 "M12 Bare Wire Cable" for connecting to meter/sensors with terminal block connections.

4-20mA Channel Details

The 4-20mA channel inputs are designed to read from 4-20mA sensors that are powered either from the switched power output source on the wildeye itself (loop powered) or from an external permanent power source.

The 4-20mA inputs on a wildeye are generally intended to read sensors that are both powered and read from the wildeye, therefore the 4-20mA device itself is powered from the wildeye SPO. Current loop sensors requiring permanent power can be supported, for further details refer to Permanently Powered Sensors.

Powering from the Wildeye SPO creates a stand-alone system fully battery powered and isolated from other noise sources and from ground. Telemetry communications are entirely wireless through the Wildeye's cellular modem, and setup is performed entirely through the mobile install app or website.

General Characteristics of the wildeye 4-20mA channel:

Single-ended (must form the last device in a 4-20mA loop if there are more than one device reading the sensor output)
200 ohm input impedance (takes 4V from the loop)
16-bit resolution, with 1% accuracy
SPO fixed at 12V (Other voltages available, for more detail see Output Power)
Tolerant to 9V permanent over-voltage applied to the 4-20mA channels

To ensure the attached 4-20mA sensor is compatible with the wildeye, the SPO stabilisation time must be set to ensure the sensor device has enough time to power up and stabilize it's output before it is sampled. The sensor device will then powered-down again.

The stabilization time for each 4-20mA channel is programmed through the website interface. See Calibrating 4-20mA Analogue Channel for more info.

Some industrial 4-20mA sensor devices are not suited to low-power operation as they have long stabilization times, in which case the sensor should be operated permanently on and powered from an external power source, not the Wildeye SPO source.

Sensor Setup

Setting up a 4-20mA sensor on your Wildeye is simple:

Check to see if your sensor has built-in support with the Wildeye Add Sensor tool. If your sensor is already supported, it is a simple case of choosing the sensor and selecting the SDI-12 address.
If the sensor is not supported via Add Sensor, you can build your 4-20mA sensor setup using standard range and stabilisation time setup. For further details see here.