Will Panel PCs Replace HMIs and PLCs?
December 06, 2016
As manufacturing in the modern industrial facility grows more and more connected, managing those processes can get more complicated.
Being able to maintain a reliable network of systems to control, track, and report on the different aspects of facility operations is becoming ever more important.
Industrial human-machine interfaces (HMIs) give operations personnel the ability to monitor production and maintain industrial assets. HMI units have been commonly used for system tasks such as sounding alarms, generating messages, capturing sensor input, transmitting data, displaying system status, controlling machines, and stopping or starting processes. When an operator enacts a change from an HMI device, a connected programmable logic controller (PLC) module then carries out the command. HMI functions handled remotely use a supervisory control and data acquisition (SCADA) system. These systems use computers, data communications, and graphical user interfaces for large-scale processes management in many manufacturing fields.
Although HMIs have been adopted in many industries as the standard machine and processing devices, there are some drawbacks. HMI screens and PLC modules are configured specifically for the one duty they need to perform, and several can be used to carry out different functions for one machine. If the device fails, a replacement device will need the exact same configuration as the original unit, or the machine will not work properly and valuable production time will be lost while another device is reconfigured. They also require the use of SCADA software to properly track and report the data to process engineers.
Panel PCs have emerged as a viable solution to the limited functionality of an HMI, as they are able to carry out all of the tasks that HMIs perform, but with added advantages. They have the storage space to hold critical reporting data, unlike HMI and PLC devices, which are forced to transmit the data to servers. In the event of a network connectivity failure, panel PCs already have data stored locally; meanwhile, if the HMI and PLC device fails and isn’t able to transmit data, the data will be lost. Panel PCs are more easily configured than highly-specialized HMI units and can handle multiple functions at once, which limits the number of interfaces needed in the facility. Panel PCs also have much better computing abilities, which improves the quantity and quality of the machine data being captured.