Data Exchange with the SM 335
3-29
SM 335 – High-Speed Analog Input/Output Module for the SIMATIC S7-300
6ES7 335-7HG00-8BA1
3.4
Evaluating SM 335 diagnostics
Methods
There are several methods of accessing SM 335 diagnostics:
•
With an enabled diagnostics interrupt via the local data in OB 82
•
With a hardware interrupt via the local data of the interrupt OB (e. g., OB 40)
•
By reading the diagnostics data with system function 59 (RD_REC)
•
Other methods: see Reference Manual System Software for S7-300/400 Sy-
stem and Standard Functions.
Diagnostics interrupt
If you have enabled the diagnostics interrupt for the SM 335 and the SM 335 gen-
erates a diagnostics interrupt, the CPU processes OB 82. The local data of OB 82
contain some of the diagnostics data of the SM 335 (see Subsection 3.4.2).
Hardware interrupt
If the SM 335 generates a hardware interrupt, this hardware interrupt can have two
causes:
•
Interrupt triggered by comparator
•
End-of-cycle interrupt
The cause leading to the SM 335 interrupt is stored in the local data of OB 40 (see
Subsection 3.4.1)
Principle
The complete diagnostics data of the SM 335 can be accessed via system func-
tion 59.
The structure of the diagnostics data is explained in Subsection 3.4.2.