Define Instruments

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  • 4 digital inputs, 2 digital outputs, and 2 relay outputs
  • Universal input: Thermocouple, RTD, mAdc, Vdc
  • 2 isolated analog outputs, 4 to 20 or 20 to 4mA
  • 9 to 36VDC (2.5VA max) power supply
  • Transmits up to 0.9 miles line of sight
    • 300 to 500ft for interior applications
    • Go farther with antenna upgrade or repeaters
  • 35mm DIN rail mount construction, IP20 rated
  • Requires a USB Bridge Key in order to program
  • FCC & CE approved
  • 5-year guarantee

What's in the Box

  • Input node (P2P-I)
  • Output node (P2P-O)
  • Two 3DBi monopole antennas

The Define Instruments Twin Link point-to-point wireless system consists of an input node and an output node which transmit signals over a distance for remote control and communication. The Input node has two universal isolated channels, accepting a range of inputs such as TC and RTD, mA and V, NPN/PNP, potentiometer, and AC current sensors. The Output node provides two 4-20mA isolated analog outputs for retransmission to PLCs and SCADA systems.

The addition of a repeater will extend the range of your Twin Link system by up to 0.9mi (1.5km) line of sight per repeater. Up to 15 repeaters can operate in a single point-to-point system, increasing the total possible transmission distance to 14.9 miles (24km). Both the Twin Link and repeaters when used with the supplied 3dBi antenna provide FCC approval, however upgraded antenna models do not. The WG-8dBi monopole antenna increases transmission range to 2.5 miles, the WG-12dBi provides 3.1 miles, WG-19dBi up to 8.1 miles, and WG-24dBi up to 16.1 miles. Signals will transmit through stud walls, brick and concrete, however the distance the signal will travel is reduced when obstacles are present.

Download the free ToolBox software to set up the Twin Link system. Select from a wide range of pre-calibrated input types, easily scale your analog outputs, and configure your IOs for mimicking, alarms, and sophisticated remote control of other equipment. Connect the P2P-I to your PC via the required USB bridge key to configure all input, output and setpoint settings, mesh ID, and wireless transmit power. The only setting that can be configured on the P2P-O is the wireless transmit power.

Required Components

These additional components are required for the operation of your product. We strongly advise you to purchase these components unless you already own them or own a suitable alternative.

Define Instruments Bridge Key Communications Kit
PC connection to all USB-programmable Define Instruments, required for Zen, Javelin, Twin Link, Sentry, Merlin, Pathfinder & TM Series
In Stock


Please consider these optional accessories.

Define Instruments Point-to-Point Wireless Repeater
Extends the wireless range of the Twin Link by relaying data between the input and output nodes
In Stock
Define Instruments 12VDC Power Adapter
Compatible with all Define Instruments wireless models
In Stock
Define Instruments Antenna Extension Cable
30cm (approximately 1ft) cable separates antenna from point-to-point transmitter for mounting unit in an enclosure, negates FCC approval
In Stock
Define Instruments Monopole Antenna
Replacement antenna for Define Instruments wireless models available in 3 or 8dBi
In Stock
Define Instruments 24V Power Supply
Powers up to ten 4-20mA, 2-wire loops with overload protection, low noise, and 2% accuracy in a DIN rail mount case


This product can be used in the following applications:

Application Notes

Here's how some of our customers used this product.

Remote Tank Level Monitor

The Background: Our customer is an industrial facility that needs to monitor the level of water inside a large holding tank.

The Problem: The holding tank is some distance away from their control room and there are no wires run nor does the customer want to run wires.

The Solution: We suggested the Define Instruments Twin Link point-to-point wireless system along with a Keller Acculevel level transmitter and a Define Instruments Merlin digital indicator. This system is set up to transmit both the liquid level to the Merlin panel meter as well as an alarm output to a warning light a distance of several hundred yards so the customer can monitor the level at a glance from their control room.