EUROTHERM has released a Procon Ethernet-based eight-channel thermocouple input module.
The MMTCP8TCISO is a Modbus TCPIP slave interface that allows up to eight thermocouple inputs to be monitored, with the information directly accessible to users over any existing Ethernet network.
It uses differential inputs to reduce the effects of electrical noise and mains pickup. The thermocouple inputs are isolated from the logic and from each other. The thermocouple voltage is linearised and converted to °C. No ranging is required as the module covers the full temperature range of the thermocouple. The value that is read from the Modbus register is the actual temperature down to 0.1°C resolution. A value of 3451 therefore corresponds to a temperature of 345.1°C. Downscale burn out can also be set. The module has built in cold junction compensation. The input can be configured for 12 different thermocouple linearisations as well as being configured for a 0mV to 50mV linear input range.
Each module has a unique Ethernet IP address which must be programmed into the PC or PLC. The IP address is configured via the Web server. Any standard Web browser can be used to access the Web pages where configuration is carried out. The converters are factory programmed with a default IP address which can be changed to add to an existing network.
The MMTCP16DI communicates using the standard Modbus/TCP protocol. This protocol is supported by many of the SCADA packages currently available. The result is a very simple and efficient way of interfacing digital input devices to a PC or PLC on an Ethernet network. The converter supports four TCP sockets. This means that up to four devices can communicate with the serial communication modules via the converter at any one time, which also eliminates the problems associated with multiple master communication conflicts which occur on a serial network.
The thermocouple inputs can be cost effectively interfaced with and being Ethernet based the number of I/O modules that can be communicated with is virtually limitless.
The MMTCP8TCISO is part of the MMTCP family of Ethernet based I/O modules allowing fully distributed analogue and digital I/O to be cost effectively monitored and controlled over a any standard existing Ethernet network, directly to a users PC.