Siemens SM 1231 Series PLC I/O Module for Use with CPU 1211, CPU 1212, CPU 1214, Analogue

Do you need to take precise temperature readings during your industrial automation processes? Opt for this PLC I/O module from Siemens. Its a resistance temperature detector with eight resistance thermometer inputs that support copper, nickel and platinum sensing elements to deliver a wide measurement range from -200°C to +850°C. To enable an attached PLC to respond to temperature data, this module converts the analogue input signal to a digital value. Use it with a Siemens SIMATIC S7-1200 series CPU to put together a modular PLC system that meets your needs.

• 15-bit+ sign resolution offers a high level of accuracy
• Operating temperature range of -40°C to +70°C for use in extreme environments
• IP20 rating indicates the unit is safe to touch
• LED indicators and integrated diagnostics functions simplify fault detection for straightforward maintenance

An RTD like this one uses the principle of temperature resistivity. As the temperature of a metal increases, so does its electrical resistance. Platinum, copper and nickel have a predictable relationship between temperature and resistance. This means that as a current passes through a sensor containing one of these metals, a measurement of the resistance can determine the temperature value.