Safety position, standstill, direction and speed detection
In many cases, safe standstill detection is indispensable. Safe speed limits may be required for servicing and setup purposes. Nevertheless, hazards can also occur if a desired position is not reached or a prohibited position is approached.
This leads to the question how machine movements can be detected whilst keeping safety in mind.
For the safe detection of machine movements, SIEMENS drives with integrated safety functions (for example, SINAMICS G120) offer various applications.
Another option is the use of safe position encoders. In combination with a SIMATIC F-CPU, these securely detected values of the F position encoder can be processed further and corresponding responses can be triggered. This application example describes the application of such an encoder.
The function example shows you how you can easily integrate an F position encoder in PROFINET. As a result, you can realize a number of safety-relevant issues with the F-CPU.
In this example, the following issues are introduced:
- Safe standstill detection
- Safely limited speed (SLS)
- Safe direction detection
- Safe position detection
Providers of failsafe position encoders are, for example:
The present example was realized with the fail-safe position encoder CDV75M by TR Electronic (SIL CL 3 / PL e / cat 4).
In terms of safety, these applications fulfill a safety integrity level up to SIL 3 in accordance with IEC 62061 or PL e in accordance with ISO 13849-1.
Documentation and Example Project
Documentation (1,1 MB)
Example project for STEP 7 V13 SP1 (13,4 MB)
Evaluation of the safety function as SET project (6,6 KB)
Migration of the application example to STEP 7 V13
Migrating the controller to S7-1500
Replacing the F position encoder with PB with an F position encoder with PN
Correction in the Archive files: Change adress I7.0 to I8.0
Encoder, SLS, Safely Limited Speed, absolute encoder, incremental encoder