Modules for the PDW90 base station are easy to install and add functionality to the wireless system. There are four types of modules available: dual analog inputs, dual analog outputs, digital I/O, and dual relays. The analog outputs module allows the base station to output two independent analog signals being broadcast by any of the field units. The analog inputs module allows the base station to accept two analog signals and transmit them wirelessly to any of the connected field units. The digital I/O module contains four channels which can be programmed to correspond with any of the field units’ digital inputs or outputs. The dual relays module can also be controlled from any of the connected field units’ digital I/O.


  • Easy to Install
  • Adds Functionality to the PDW90 Wireless System
  • Can Utilize up to 16 Modules in PDW90 Base Station
  • Dual Analog Inputs Module
  • Dual Analog Outputs Module
  • Digital I/O Module
  • Dual Relays Module

Dual Analog Input Module


Field selectable: 4-20 mA, 0-10 V, 0-5 V, 1-5 V


±0.03% of calibrated span ±1 count


500 V


All ranges are calibrated at the factory. Recalibration is recommended at least every 12 months.

Temperature Drift

0.005% of calibrated span/°C max from 0 to 65°C ambient,
0.01% of calibrated span/°C max from -40 to 0°C ambient

Input Impedance

Voltage ranges: greater than 110 kΩ; Current ranges: < 220 Ω

Signal Loss

Inputs will remain off (open circuit) until wireless units are reconnected.

HART Transparency

Analog input will not interfere with existing HART communications on the wired 4-20 mA signal

Dual 4-20 mA Output Module

Output Source

Analog input from connected wireless unit


Factory calibrated: 4.000 to 20.000 = 4-20 mA output


± 0.1% of span ± 0.004 mA


500 V

Temperature Drift

0.4 µA/°C max from 0 to 65°C ambient,
0.8 µA/°C max from -40 to 0°C ambient

Loop Power Supply

Internally powered; no external supply needed

Output Loop Resistance

Power supply



24 VDC

10 Ω

900 Ω

Signal Loss

After approximately 25 seconds of trying to reconnect, mA output will become 3.2 mA

Digital Input / Output Module


Four (4) digital connections, independently field selectable as either inputs or outputs

Digital Input Logic High

3 to 5 VDC

Digital Input Logic Low

0 to 1.1 VDC

Digital Output Logic High

3 to 5 VDC

Digital Output Logic Low

0 to 0.4 VDC

Source Current

10 mA maximum output current

Sink Current

1.5 mA minimum input current

Signal Loss

Digital output goes to logic high

Dual Relays Module


2 SPDT (Form C); rated 3 A @ 30 VDC and 125/250 VAC resistive load; 1/14 HP (≈ 50 W) @ 125/250 VAC for inductive loads


Noise suppression is recommended for each relay contact switching inductive loads; see page 13 for details.


After power failure, relays will initialize to default state before reconnecting to wireless units.

Signal Loss

If mapped to digital input channel, the relay energizes.


Base Station

The diagram below shows the locations of screw terminal blocks on a fully loaded PDW90 base station electronics board. This diagram shows the board loaded with four relay modules, four digital I/O modules, four analog input modules, and four analog output modules. Actual module locations may differ.


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