In industrial machinery and equipment, most control systems utilize PLCs (Programmable Logic Controllers) to achieve efficient and precise control. PLCs are the "soul" of a machine, a crucial component showcasing its capabilities. Early PLCs were vastly different from today's models in terms of processing speed, expandability, and applicability. With technological advancements, industrial control professionals have increasingly higher demands for PLCs ; previously, simply having them functional was sufficient, but now they must be highly efficient, reflecting the reliance of industrial control professionals on PLCs .
The Pilz PSS4000 programmable safety control system covers all aspects of automation control, from small-scale centralized control to large-scale complex discrete network structures. With its simple and user-friendly software and diverse hardware options, it achieves standard and safety-related functions.
In modern factories, assembly line operations involve equipment from various suppliers. These devices are interconnected to varying degrees, with some even requiring permission from another machine to operate . Therefore, effective signal communication between devices is crucial. In the past, this required programmers to undertake extensive planning in the early design phase, reserving sufficient processing space for the final application. In severe cases, this could lead to system crashes and require significant program modifications during the later stages of debugging. To address these application needs, the PSS4000 system introduced the PASconnet function, efficiently and conveniently establishing interconnectivity and relieving developers of these concerns.
In a high-voltage equipment safety interlocking system project for one of Pilz's customers, the convenience that PASconnect brings to program developers was fully demonstrated.
Project Description: This project involves applications in two workshops. The laboratory workshop has a complete high-voltage testing system to conduct high-voltage withstand tests on products and generate reliability reports. Before product testing, a series of safety function confirmations are required for the on-site conditions, such as whether safety doors are closed and fences are shut. High-voltage testing can only proceed after these conditions are met. The factory workshop also has high-voltage testing needs, but the demand does not meet the requirements for adding additional equipment. Therefore, for economic and efficiency reasons, the high-voltage testing equipment in the factory workshop is "downgraded" and becomes a testing branch of the laboratory equipment. In other words, the factory workshop's testing requires it to meet its own conditions and obtain permission from the laboratory before it can perform testing work, while the factory workshop's operating conditions need to be monitored in real time by the laboratory equipment to prevent accidental activation. Therefore, these two seemingly independent entities operate seamlessly together. Due to significant differences in the time of equipment deployment, functional requirements, and other aspects between the two workshops, and because the financial operations of the two workshops are calculated independently, each workshop's control system is an independent system. Such application requirements, if used in early PLC systems, would place stringent demands on the initial equipment system, and this system must possess sufficient flexibility to prevent system collapse due to later modifications. Now, however, by simply building the hardware of two independent systems within the same closed-loop network and using the PAS Connect function, the two projects can be easily interconnected without affecting their respective independent control structures.
Hardware specifications:
A. Factory Area
B. Laboratory Area
PAS Connect Features Overview
The PAS Connect function refers to the data exchange between PSS 4000 devices in different PSS 4000 projects via FS/ST SafetyNET p RTFN . It's important to emphasize that the transmitted data is not limited to the previously supported standard types, but also includes safety types, although the data length limits differ: FS-Tx connections (safety type) can transmit up to 118 bytes of FS process data; ST-Tx connections (standard type) can transmit up to 251 bytes of ST process data. Data types must be basic data types; derived data types are not allowed, such as ARRAY data types (arrays) or STRUCT data types (structures). Combined with the PASconnect software, data I/O mapping between different projects is implemented .
Below, we will demonstrate in more detail how PASconnect enables cross-project communication:
The following settings are required for each project ( PAS4000 software):
1. In each project, generate interactive variables (the variable type must be a process image variable).
2. Access the settings interface through the " PASconnect Interface" menu.
3. Activate the “ PAS Connect interface” function and set the data storage path.
4. Add the data to be interacted with.
5. Generate a PASconnect sub-project (an XML file), which is stored in the path specified in step 2 .
Use PAS Connect software to perform the next mapping step:
1. After creating a new project, import the PASconnect sub-project ( the XML files of the two projects ) that were previously generated using PAS4000 software .
2. Enter the " IO Mapping Editor " section to proceed with the next step of data mapping.
3. Select the corresponding item in the "Data Source" and "Data Target" sections to see the corresponding matching data.
4. Select the data that needs to be matched one-to-one (data types must match), and click the "Execute" button in the middle. Matched data will be highlighted in color. After completion, you can repeat step 3. The complete list of matched data is shown below for easy confirmation and tracking.
5. After completing the mapping of the data, you must execute the " Create output data " step; otherwise, the PSS4000 project will fail to compile.
Now, each PSS4000 project can be compiled. After successful compilation (without error messages), the program can be downloaded, enabling cross-project communication.
During the project, if data is deleted, added, or the mapping content is changed, the above steps can be modified accordingly based on the actual situation, making it highly flexible, intuitive, and convenient.
Project Advantages: During the design and commissioning phases of the laboratory system, although the requirements for the factory area system were still somewhat vague, this did not affect the system's deployment and operation. Once the control requirements for the factory area system were clearly defined, and the content of information exchange between the two areas was clarified, the laboratory system could be quickly modified to seamlessly integrate control and feedback from the factory area system, reducing downtime for the laboratory system while expanding its operational capabilities. The logical relationship between the factory area system and the laboratory system was clearly defined during the design phase; only the data relationships needed to be clarified. For the designers, whether it was writing the program or conducting later project debugging, executing the project was a breeze.
Pilz actively maintains close contact with its customers across all sectors through personalized consultation, high flexibility, and reliable service. As an automation solutions provider, we offer not only sensors, drive and control technologies, but also services related to automation and machine safety. Pilz is always customer-centric, earning the trust of its customers with high-quality products, innovative systems, and superior service.
