How to Measure Temperature, with a High-Density Ethernet I/O Solution
An Acromag Application Note
The Problem: Monitoring up to 500 Temperature Measurement Points
A chemical manufacturer has up to 500 temperature measurement points. In addition, they’re monitoring points for pressure, level and flow, and have thermocouple and RTD scattered throughout their process. It would be cost prohibitive to run and maintain twisted pair wire for all these points, both initially and in the long term. Further, the number of IP addresses on their network determines their SCADA system license fee. With remote I/O temperature units averaging 4 to 6 channels each, this could also be costly. As a result, Ethernet is the preferred solution.
Temperature Measurement with Ethernet I/O – System Requirements:
The manufacturer’s Honeywell Experion® SCADA system utilizes Modbus® TCP/IP protocol. The remote I/O needs to be a Modbus server which accepts a mix of thermocouple and RTD signals. Therefore, higher channel density is preferred.
The Solution: BusWorks NT
Acromag’s BusWorks NT series of expandable remote I/O was a great fit for this application. The NT modules are configurable in the field for Modbus TCP/IP, Ethernet IP™ or Profinet® protocols, and have more protocols coming. This series consists of a base unit with two ethernet ports (NTE). The NTE can be populated with discrete I/O, analog inputs, analog outputs, thermocouple, or RTD. Given these points, the key here is that you can plug in up to three expansion units (NTX) of the above I/O in any combination. As an illustration, the thermocouple units have 8 input channels, and the RTD units have 4 input channels. So, if at one point of the process you paired one NTE-2611-1111 with two NTX-2611-0011 and a single NTX2621-0011, you would have 24 thermocouple channels and 4 RTD channels and only a single IP address.
Learn more about the NT Series here.
Acromag NT Series:
NTE2611-1111: Ethernet I/O module with dual RJ45 ports, 8 thermocouple/mV inputs and 2 discrete I/O.
NTX2611-0011: Expansion I/O module with 8 thermocouple/mV inputs and 2 discrete I/O.
NTX2621-0011: Expansion I/O module with 4 RTD/resistance inputs and 2 discrete sinking I/O. (Coming soon.)
The BusWorks NT series has built-in web pages for easy configuration and testing, so it relieves the user of needing extra hardware and software. Additionally, the flexibility to add expansion units of any type of I/O allows a unique solution at each location. NTs are built for rugged environments, with approvals for up to 20g shock and 4g vibration, extreme temperature operating ranges, as well as UL/cUL Class 1; Div2; and ATEX/IECEX Zone 2 (pending) safety ratings.
Acromag is a Michigan-based manufacturer that has been in business for over 60 years. Acromag products are all manufactured in the USA.