Diagnostics in SIMATIC STEP 7

There is a comprehensive diagnostics function block available for SIMATIC S7-300/S7-400. This automatically reads-out the diagnostics data from the AS-Interface safety monitor. The status of the logic blocks in the safety monitor can be directly transferred to the control (PLC) via the AS-Interface bus. From there, information e.g. can be output on an operator display (HMI) or saved in an archive. This diagnostics package also includes a function block to diagnose the master – and can be used to read-out the system status from the AS-Interface master. This is realized independently of the safety monitor and can also be used for a pure standard AS-Interface network. An appropriate diagnostics subroutine is also available for the S7-200 small control system.