Glossary · PLC and control programming
PLCopen
Also known as: PLCopen organization
German: PLCopen
PLCopen is an independent, vendor-neutral association that promotes IEC 61131-3 and publishes specifications that build on it, such as the motion control function blocks, safety function blocks, the PLCopen XML exchange format and coding guidelines.
- PLC programming
- Standards
In one sentence
PLCopen is a vendor-neutral association promoting IEC 61131-3, publishing motion control, safety and XML exchange specifications.
Example
A machine builder uses the PLCopen motion control blocks MC_Power and MC_MoveAbsolute so that its axis logic looks the same on controllers from two vendors.
How it applies
- Engineering: PLCopen specifications give common names and behavior to recurring functions. The motion control specification defines function blocks such as MC_Power, MC_Home and MC_MoveAbsolute and a state diagram for axes. The safety specification defines function blocks for common safety functions such as emergency stop and guard monitoring.
- Portability: Vendors implement PLCopen specifications to different degrees. Code using the same blocks is easier to port and easier to read across teams, but still needs testing on each platform.
- Safety: Using PLCopen safety function blocks does not make an application safe or compliant by itself; the safety function still needs its specification, design and validation according to the applicable standard.
- Documentation: When a project relies on PLCopen blocks, the software documentation can reference the specification for block behavior and concentrate on the project-specific use.
PLCopen vs. IEC
IEC publishes the international standard IEC 61131-3. PLCopen is an association that promotes it and publishes additional specifications. PLCopen documents are not IEC standards.