Construct a High-Speed Data Acquisition System with Ethernet-Enabled Controllers and PLC

This introduces a system that uses Ethernet communications to acquire measured values, target values, and control output values from a controller installed on site into a PLC at high speed (ten units' worth within one second).

The Ethernet communication function that can be included with the UT55A/UT35A supports 100BASE-TX and 10BASE-T. By using the high-speed response mode that comes standard with the Ethernet function, the instruments can respond rapidly to requests for data from (upstream) PLC's and other devices. Since measured and other data are stored in the Ethernet-specific registers inside the UT, the data can be retrieved at high speeds by upstream devices by accessing those registers. Data that can be acquired with high-speed response are: PV values, SP values, OUT values, error information (PV input or A/D operation), alarm ON/OFF statuses, and other information such as RUN/STOP. Using the gateway function, you can connect with up to thirty-one other RS485-enabled (Modbus/RTU protocol) controllers via RS485. Of those, up to eight (including the UT55A/UT35A) can use high-speed response mode for high-speed data acquisition.