It is packaged in a standard ANSI - 2”, 50mm “hockey-puck” to be installed in the head of normal industrial temperature probe assembly. The TC-003 transmitter is connected to the normal 3 wire PT100 RTD.
How does Analog to Digital Pulse - RTD Transmitter work?
It measures the resistance of the PT100 RTD and then calculates the corresponding temperature. It then outputs the measurement as a low speed serial pulse train to a standard PLC digital input.
The PLC receives 16 bits of data in a format ready to load into a 16 bit data register. The PLC register ends up containing the value of the measured temperature in degrees C x 10. For example if the measured temperature is -5°C the transmitted data will be -50, and if the measured temperature is +10°C the transmitted data will be 100.
Is Analog to Digital Pulse - RTD Transmitter compatible?
The PLC digital input does not need to be a high speed or counter type input. Any normal 24VDC digital input is suitable.
The rate of data transmission is selected to allow non-time critical operation of the receiving PLC. The shortest pulse time is 100mS, so the PLC needs to have a maximum scan time of 50mS. This is normally very easy to achieve.
A small section of ladder program collects and interprets the pulses in sequence and loads a register with the measured temperature value.
There is no particular limit to the number of TC-003 transmitters that can be used with a single PLC. It depends only on the number of inputs and program and data memory available.