NSLS Control System Interface to Modicon PLC
Susila Ramamoorthy · 2001
The hardware engineering efforts at the National Synchrotron Light Source facility are currently geared towards the use of programmable logic controllers (PLCs) for the control of machine hardware. The PLC provides a cost-effective solution combined with easy maintenance and upgrade. Modicon control products from Schneider Automation Inc. have been chosen since a wide range of PLC’s, inexpensive I/O modules and networking options are offered by the company. The NSLS Control Monitor software uses the Modbus/TCP which is a variant of Modbus protocol to communicate with the PLCs. This paper describes the software interface to the Ethernet attachment on the PLCs.1