Intelligent, networked production processes can significantly increase productivity. However, this is only possible if a wide variety of data is available. Safety Device Diagnostics can provide support, and Pilz says its diagnostic system provides the necessary detailed diagnostic data.
Safety Device Diagnostics from Pilz records data such as individual device serial numbers, versions, current status and past errors. These are scanned and processed at control level via Modbus or Profibus. In future this will also be possible via Profinet or Ethernet/IP. The data is then displayed on the fieldbus module, a PLC monitor or on a computer screen via a web server.
As a result, the diagnostic data is available both on the machine and remotely for use with predictive maintenance. This is becoming increasingly important in the wake of Industrie 4.0. It applies not only with regard to the timely replacement of worn parts, but also to maintaining operational safety. By analysing the stored data, users can compare the original state with the current state at any time. That way any changes on the machine can be identified immediately, without the need for any additional hardware at control level.
Another example for Industrie 4.0 scenarios are intelligent systems for the functional safety of modular plants. The diagnostic system's linear cable structure makes it comparatively easy to add another module to the plant. There is no need for any new cabling, changes in the control cabinet or changes to the design drawings. Nor are any additional safety devices required. In combination with the PSENmlock secure safety gate system, for the first time safety gates can be controlled individually. If a plant requires maintenance work or a tool change, it is possible to define which gates may be opened after shutdown. Without Safety Device Diagnostics, all the gates would open.
IO-Link Safety as an alternative
An alternative approach is currently being developed with IO-Link Safety. This guarantees interoperability right up to the sensors. It therefore operates on all levels with safety devices from various manufacturers. Data is transferred securely from the sensor to the PLC, creating new application options. With IO-Link Safety it is the PLC that switches and not the sensor. Expensive safety architectures are specified as a result and new dependencies arise between the sensor and PLCs - for example, when a replacement is needed.
This approach is based on point-to-point connections, ie on a star configuration in the field or control cabinet. The bottom line is that both installation and engineering costs are considerably higher than with the diagnostic system. Depending on the application, the cost-benefit ratio will be the primary factor in deciding which system will gain acceptance.
In conclusion, IO-Link Safety is currently still a vision for the future, whereas Pilz Safety Device Diagnostics are ready to use now.
Follow the link for more information about Safety Device Diagnostics from Pilz.