PLC's, HMI's and Remote I/O
Programmable logic controllers are often thought of as the brains of the machine, processing much of the logic that enables a complex machine to function. Traditionally, PLCs specialized in tasks like timing, counting, and managing I/O. In recent years, these devices have become both specialized and varied. Some versions handle highly synchronized, multi-axis motion control. Others have built-in robotics capabilities, for example processing the kinematics for SCARA robots. Safety PLCs process large amounts of I/O and complex logic in order to implement functional safety. PLCs exist specifically for weighing tasks while others incorporate databases like SQL servers.
A human-machine interface (HMI) can be as simple as a push button or as sophisticated as a 15-inch diagonal, full-color VGA display. The HMI is an integral part of machine effectiveness because it determines how effectively the user can monitor and operate the equipment. HMIs are available with a variety of functions including data logging, remote access, and simple supervisory control and data acquisition (SCADA) functionality. Instead of simply showing an error code in a fault condition, they can now display a diagram of the machine pinpointing the location of the problem, then transmit recovery instructions to a portable device carried by the operator to the site of the failure. To save space and time, some HMIs are even integrated with the controller.
There was a time connectivity meant linking devices to a shared backplane that sat in the cabinet next to the PLC. Once all of the ports were full, further expanding meant adding another backplane, even if it were just to accommodate one more device. Today, field buses support modular remote I/O blocks that can be deployed out on the machine and connected to the PLC by a single cable. These I/O blocks can be increased one port at a time, adding flexibility and cutting cost while simplifying design. The reduction in cabling likewise lowers cost while reducing points of failure.
We offer devices compatible with the most popular industrial fieldbus protocols like EtherNet/IP, EtherCAT, DeviceNET, PROFIBUS-DP, and CompoBus/S. This level of communications speeds commissioning while enabling predictive maintenance and energy auditing.