Measurement system takes up to 32 temperatures

A Moore Industries International product story

Edited by the Engineeringtalk editorial team Aug 22, 2008

System provides a precision measurement at less than 25% the cost of using comparable stand-alone smart temperature transmitters.

The TCS temperature concentrator system from Moore Industries substantially reduces the cost of transmitting multiple temperature sensor measurements by concentrating up to 32 signals onto a single twisted wire pair.

The system provides a precision measurement at less than 25% the cost of using comparable stand-alone smart temperature transmitters.

The TCS accepts any combination of RTD, T/C, millivolt and resistance/potentiometer signal inputs, converts the inputs to the Hart digital communications protocol, and transmits the data long distances from the field to the control room on an economical Hart digital datalink over a twisted wire pair.

All process, status and diagnostic information can then be accessed by a Hart-based control system.

"As we all know, manufacturing companies are continuously looking to reduce costs".

"To do this, some are moving away from stand-alone transmitters to lower cost per point temperature bricks", says Tina Lockhart, Moore Industries' Director of Engineering.

"Saving real estate also equates to reduced overall costs".

"At less than 5in wide, each of our TCS modules will handle 16 measurements in a fraction of the space required by stand-alone transmitters".

In addition to savings realised in instrument and space costs, the TCS uses Hart - or Modbus RTU with a convertor module - for communication from the field to the control room.

One twisted wire pair replaces expensive dedicated wires.

The TCS, being a loop-powered device, eliminates the need to send power wiring out to the field as well.

Using Hart, maintenance personnel can access programming and status information for each TCS channel from the control room, or from any termination point using a standard Hart handheld communicator.

There's no need to send someone to remote sites.

"In developing the TCS, our greatest challenge was to provide our customers with the cost savings they want, yet still maintain the full functionality and exceptional product performance they expect from a Moore Industries temperature transmitter", Lockhart adds.

When used with the optional HMC Hart-to-Modbus convertor, the HMC transmits the Hart data as a Modbus RTU signal, which interfaces with any Modbus RTU-based PC, PLC or control system.

The HMC can be programmed via the PC software to provide two relay outputs.

The relays can be set to send a master alarm when the HMC detects one, any, or all of the following fault conditions within the system: No Hart signal; broken wire; hardware error; bad configuration; input saturated; and input out of table range.

The alarms can be set with a time delay, which specifies how long the alarm condition needs to exist before the alarm trips.

Failsafe and nonfailsafe alarm action is also configurable.