Siemens SIMATIC SM 335 - How Comparator Mode Works

Special SM 335 Operating Modes
5-4
SM 335 – High-Speed Analog Input/Output Module for the SIMATIC S7-300
6ES7 335-7HG00-8BA1
5.2.1 How comparator mode works
Three methods
Comparator mode provides three methods of comparing a measured analog value
with a specified analog value:
• Comparator 1: As in normal mode, measuring at the parameterized inputs. Si-
multaneous comparison of the comparator input with a comparison value: when
a comparison value is reached, a hardware interrupt is generated and the spe-
cified analog values are output.
With Comparator 1, the analog inputs can be accessed using peripheral input
words.
• Comparator 2: Measuring only at the comparator input. When the comparison
value is reached, a process interrupt is generated and specified analog values
are output.
With Comparator 2, the comparator input value cannot be accessed.
• Connection of Comparator 1 to Comparator 2 in series.
Comparator 1 does not generate a hardware interrupt and does not output any
analog values, but switches to Comparator 2.