System and method for controlling a process line using a PLC and scalable HMI control template

A control system for use with a process line having a plurality of workstations and a plurality of human machine interface (HMI) devices, the control system comprising:

• a plurality of sensors operable for measuring or detecting a state of a device used in a corresponding one of the workstations;
• a plurality of actuators responsive to control signals;
• and
• a programmable logic controller (PLC) in networked communication with the HMI devices and the actuators, having a calibrated clock cycle, and programmed with a plurality of control and monitoring functions for the process line, wherein the PLC is operable for outputting the control signals to the actuators in response to input signals from the HMI devices and the sensors to thereby control operation of the process line;
• wherein the PLC is provided with a plurality of control screens each having a unique screen number, and is configured to:
• provide access via each of the HMI devices to a first set of the control screens;
• receive input signals from a requesting one of the HMI devices that identifies the requesting HMI device and requests one of a control action and a monitoring action for a corresponding one of the workstations;
• provide the requesting HMI device with access to a second set of the control screens based on the received input signals, such that the plurality of HMI devices share an HMI control template that is also dynamically and individually scalable to the requesting HMI device;
• control the process line via the PLC in response to control signals from the HMI devices corresponding to selections from the first and second sets of control screens;
• determine, as an HMI scan at the end of each clock cycle using the counter, whether active communications remain ongoing between the PLC and the HMI devices;
• increment the counter via the PLC when the active communications are not ongoing;
• reset the counter when the active communications are ongoing;
• and
• indicate a fault when the counter reaches a calibrated number of the HMI scans.