Centralized machine control is more than a control architectural scheme, it’s the first step to enabling Industrial Internet of Things (IIoT). The Parker Automation Controller (PAC) provides this central architecture as it is an all-in-one device responsible for handling PLC logic, commanding high precision motion control—including robotics—and provides embedded human-machine interface (HMI).
For the programmer, this means that they don’t need to share tags between devices or fuss with multiple control networks, because all the machine components are on the same device using the same logic. This is critical to IIoT as it allows the flow of accurate, actionable data to easily transfer within the machine and out to the user or server who can make critical decisions with that data.
Take for example a motor overheating: Traditionally, the temperature within a motor was not even monitored so a motor overheating would not be detected until there was a critical over-current failure. If the amplifier was connected to a motion controller over a bus network, it may be able to communicate the type of failure back to the drive—if it wasn’t connected to the bus, which is still common, the motion controller may construe the error simply as a “position error.” The motion controller, usually connected to the PLC over a different type of communication bus, may then be able to communicate some type of error to the PLC but may be restricted to only communicating a bit which represents “error.” The PLC passes on the error out to the HMI, potentially over another bus type with its own constraints, to finally display “Machine error” on the user screen.
Perhaps a better case may specify where in the machine the failure is occurring such as “Conveyor not starting.” Even though the data is presented out to the operator, it’s the maintenance person who needs to repair the machine. The maintenance personnel are only notified when called—thus, the operator may try to repair the machine themselves or may incorrectly describe the maintenance issue exasperating the issue and increasing down time. This lengthy game of data-telephone is an all-too-common occurrence in the factory floor. The real tragedy? If you trace this situation back, the data is available it’s just not easily accessible to the right audience.
Now, compare the same motor heating issue with a machine using the PAC, an all-in-one motion control, PLC, and embedded HMI. Since the PAC is controlling and commanding the drives, it can directly query the temperature information. The PAC is also responsible for the PLC logic, and thus the PAC can be programmed to check that the temperature data is within normal operating constraints. If the temperature goes out of this range, the HMI—which uses the same PLC logic—not only can notify the operator, but because it’s a web server, can send an e-mail to the maintenance person of the exact issue, which axis is being affected, and even the current temperature. That is what we mean by complete ease of data flow and is only achievable if the machine is controlled through a single device.
Sounds easier said than done, right? Wrong! The PAC is programmed with the Parker Automation Manager (PAM) which allows users to program their entire machine (PLC logic, embedded HMI, and motion control) in one single integrated development environment. Taking advantage of IEC 61131-3, a standard PLC language, which includes ladder and structured text developers will already be familiar with how to program the PAC. In addition, the embedded HMI on the PAC, called WebVisu is programmed in the same environment. Any client connected to the local network such as a browser, or mobile device using Parker’s Remote Manager (RemoteMgr) app, can connect to WebVisu in the PAC simply by entering in the PAC’s IP address and target application.
User management tools within PAM allow developers to create various user groups with different read/write access to different screens or to specific objects. This ensures that the right information can be projected to the right users. This functionality is often called “fog” computing—a subset of IIoT that does not require going to any external cloud server giving both the machine builder and the factory full control of the data set while achieving the promise of IIoT—Information Anywhere.
The first step to achieving fog-based IIoT is to ensure that all the devices in the system are reporting out to a centralized controller which acts as a gateway. The PAC can both process and perform logical tests on the data it receives from the sub-devices but can also serve it up locally or remotely via the embedded WebVisu HMI. This ensures that data is turned into actionable information and then sent to the right audience. In addition, the PAC is also OPC enabled, meaning that it can send information to a database for future retrieval or for communicating with an already existing SCADA, MES, or OT system. Such as system or server may then be cloud-connected. For low-level devices which need sensors added on—consider using IO-Link. This low-cost, low bandwidth serial protocol allows previously “dumb” devices to provide useful information back to the centralized controller enabling new insights into a machine and perhaps allowing for new opportunities for preventative maintenance.
There is a lot of noise for IIoT right now. What gets lost is that there is no one solution for IIoT. Machine builders, factory managers, and business executives are having to work together to come up with an architecture that works for their system and their unique needs. What gets lost in all the noise is that the cloud is not the only answer—it’s one part of the greater solution. User case stories are central to implementing a useful IIoT system as many of these users’ needs can be solved with centralized control and providing IIoT on the fog computing layer. This architecture is also future proof and allows for growth into the cloud if needed, the trick is to prepare and plan today.
Article contributed by Marissa Tucker, product marketing manager, Electromechanical & Drives Division North America, Parker Hannifin Corporation.