A dedicated four-channel Pt100 / Pt1000 measurement architecture was developed around the required temperature inputs.
Start a Project ↗CASE 01INDUSTRIAL MEASUREMENT
Replacing costly PLC expansion with application-specific measurement hardware.
A machine manufacturer needed four-point RTD temperature acquisition without the cost of additional PLC temperature input hardware, in an environment where EMC performance mattered from the start.
APPLICATIONIndustrial machinery
CORE REQUIREMENTFour-channel Pt100 / Pt1000 measurement with Modbus RTU communication
DEVELOPMENT SCOPEMeasurement electronics, isolated communication, pre-compliance and production
STATUSOngoing white-label production
01THE REQUIREMENT
Four temperature measurements.
Without another costly PLC expansion module.
The customer was developing a new machine and needed temperature information from four Pt100 / Pt1000 RTD sensors to be available to the existing control system over Modbus RTU.
Dedicated PLC RTD expansion hardware would have increased the machine cost, so the measurement requirement was moved into a purpose-built module.
02THE ENGINEERING CHALLENGE
Measurement hardware for an
electrically demanding machine.
The module would operate inside high-power industrial machinery, where electrical noise could affect measurement, communication and overall system performance.
Because the completed machine would undergo CE conformity assessment, EMC behavior had to be considered during development rather than after the hardware was finished.
03THE ENGINEERING
Purpose-built around the requirement.
SYSTEM ARCHITECTURE
4 × RTDPt100 / Pt1000 inputs
→MeasurementRTD acquisition
→IsolationSignal separation
→RS-485Modbus RTU
→Machine ControlExisting PLC
DESIGN CONTEXT
Measurement accuracy, interface isolation and EMC behavior were treated as one system problem.
Modbus RTU communication was implemented over an isolated RS-485 interface for integration with the machine control system.
Filtering and transient protection were incorporated into the power and sensor interfaces for the electrically demanding environment.
The hardware was evaluated in an accredited laboratory before series production, including EMC-related pre-compliance work relevant to the final machine.
04THE OUTCOME
Lower system cost.
Validated hardware. Ongoing production.
The custom module met the customer’s cost target without adding costly PLC RTD expansion hardware, while retaining the isolation and robustness required for a demanding industrial machine environment.
Following validation and integration, the machine proceeded through its required CE conformity process. The module subsequently moved into production and continues to be manufactured as a white-label product for the customer.
ENGINEERING CASES