D1450M Modbus Modules with Thermistor Input


The D1450M thermistor input modules contain an isolated 15-bit analog to digital converter and measure thermistor temperature sensors. Thermistors are temperature sensitive resistors that exhibit a predictable change in resistance vs temperature. Modules are available to measure either the 2252 Ohm or the TD series thermistors.

The D1450M module performs all signal conditioning, analog to digital conversion and linearize the digital data. The digital data values are scaled into 16-bit unsigned integer data format that represent a percentage of the full-scale input range. The data values are transmitted to a host computer using the Modbus RTU serial protocol via an RS-232 or RS-485 serial port.

The D1450M thermistor input modules contain one discrete digital input and two open-collector digital outputs. The digital outputs can be used to control solid-state relays and annunciators.  They can be pulled up to +30Vdc and sink up to 30mA without damage.  The discrete digital inputs can accept +/-30Vdc signals without damage.  The discrete switching levels are <+1Vdc = logic “0”, >+3.5Vdc equals a Logic “1”.

Because the Modbus protocol does not support Echoing the RS-232 versions of D1000M series are limited to one module per serial port. Applications requiring more than one module should use RS-485.

Use the links below to download a Datasheet, User’s Manual or view the Modbus Scaling Example.

Download Datasheet

Download Manual

Modbus Scaling Overview

The D1450M series modules can also be mounted on a DIN-Rail using the MK-1 mounting kit.

2252: -0 to +100 C
TD: -40 to 150 C

2252: +/-0.1 C
TD: +/-0.2 C

Additional Information

Dimensions 3.6 × 2.45 × 1.1 in

• Thermistors: 2252 Ohm at 25 Deg C, TD Series.
• Resolution: 0.01 degrees C or F.
• Common mode rejection: 100db at 50/60Hz.
• Input protection to 30Vdc.
• Two open-collector digital outputs.
• One digital input.


RS-232 Only, RS-485 Only

Click outside to hide the comparison bar