Siemens SIMATIC S7-300 FM 350-1, Руководство пользователя

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Operating Modes, parameters and commands
7.3 Count modes
FM 350-1 Counter module
90
Manual, 05/2011, A5E03648639-01
7.3.3 Endless counting
Overview
In this operating mode, the FM 350-1 counts continuously from the count value:
●
If the counter reaches the high limit when counting up and a further count pulse is
received, it jumps to the low count limit and continues to count from there without any
pulse losses.
● If the counter reaches the low limit when counting down and a further count pulse is
received, it jumps to the high limit and continues to count from there without any pulse
losses.
The following applies to the 31-bit count range:
●
The high count limit is set to +2 147 483 647 (2
31
- 1).
● The low count limit is set to -2 147 483 648 (-2
31
).
The following applies to the 32-bit count range:
●
The high count limit is set to +4 294 967 295 (2
32
- 1).
● The low count limit is set to 0 (zero).
Behavior at the Count Limits
If the counter reaches the high or low count limit and a further count pulse is received, then
the counter is set to the other count limit. An appropriate status bit is set in the DB.
Table 7- 5 Behavior at the Count Limits (Continuous Counting)
Count limit reached Status bit in DB
High count limit STS_OFLW is set
Low count limit STS_UFLW is set