Special SM 335 Operating Modes
5-11
SM 335 – High-Speed Analog Input/Output Module for the SIMATIC S7-300
6ES7 335-7HG00-8BA1
Comparator time (DS1, byte 10)
While Comparator 2 is active, the SM 335 can not generate a hardware interrupt
for end-of-cycle. It is therefore possible that the SM 335 will fail to generate an
end-of-cycle interrupt for a longer period of time. You can set the Comparator Time
parameter to define the amount of time the comparator may remain active. If the
comparator time expires while the comparator is active, the SM 335 automatically
returns to Free Cycle or Conditional Cycle mode. The comparator time is specified
in milliseconds (1 = 1 ms, 2 = 2 ms, up to 0 = 256 ms).
The set comparator time is acknowledged in the local data of the OB 40, as long
as a corresponding hardware interrupt has been generated by the SM 335
(see also Subsection 3.4.1, Table 3-17)
Dynamic Measuring Cycle Control (DS1, byte 11)
The Dynamic Measuring Cycle Control byte has the following format in “Compara-
tor Mode 1”:
7
6
5
4
3
2
1
0
= 0: Deactivate mode
= 1: Activate mode
“Measuring Only” mode
“Comparator” mode
Comparator mode
Analog input of
Comparator 1
00 – Analog input CH0
01 – Analog input CH1
10 – Analog input CH2
11 – Analog input CH3
Analog input of
Comparator 2
00 – Analog input CH0
01 – Analog input CH1
10 – Analog input CH2
11 – Analog input CH3
= 1:
Fig. 5-7
Meaning of bits in the “dynamic measuring cycle control” byte (Comparator)
The “Dynamic Measuring Cycle Control” byte has several functions.
•
Activation of “Measuring Only” mode
•
Activation of “Comparator” mode
•
Allocation of comparator
