The Allen-Bradley 1790D-T4T0 4-channel DeviceNet thermocouple base module has been designed and manufactured as a dedicated 4-channel input thermocouple base module for the DeviceNet networks. It can read and interpret the temperature readings that are generated by thermocouples, which are a type of temperature measuring instrument consisting of 2 electrical conductors made of different materials, which form an electrical junction together. When this junction senses a temperature reading, it reacts with a voltage variation that can be correlated with the original temperature variation. The Allen-Bradley 1790D-T4T0 4-channel thermocouple base module for DeviceNet is used to collect these small voltage signals from the thermocouples, digitalize them, and to transmit them to the facility’s central processors through a DeviceNet industrial network.

The Allen-Bradley 1790D-T4T0 4-channel DeviceNet thermocouple base module provides 4 thermocouple inputs,which can handle small voltage signals in the order of millivolts (mV). The rated input voltage range goes from -76.50 mV to 76.50 mV. The supported sensors are thermocouples that are Type B, E, J, K, R, S, T, N, and 10 microvolts thermocouples. They come with a resolution of 16 bits, 0.1 degrees Celsius/bit or 0.1 degrees Fahrenheit/bit (for the thermocouple sensors). The 1790D-T4T0 thermocouple base module scans the 4 input channels every 140 milliseconds by using a notch filter set at 60 Hertz. Its accuracy is rated 0.2% at a full scale in the 0 to 55 degrees Celsius temperature range. Open wire detection is supported and it will be shown as an “out of range” message in the user’s processor. The DeviceNet power supply should be rated at 24 Volts DC, and the module is capable of operating with a minimum voltage of 11 Volts DC or 8.8 Volts DC.