Siemens simatic s7-400 FM 450-1 - Page 85

Modes, settings, parameters and commands
8.12 Initiating a process interrupt
Counter module FM 450-1
Manual, 02/2014, A5E03648739-02
85
Setting counter with input 1I2 (2I2)
A counter can be loaded with the load value via a rising edge at input 1I2 (2I2).
You can specify the behavior of an FM°450-1 counter with a positive edge at input 1I2 (2I2)
with the ENSET_UP and ENSET_DN variables in the DB of the FC_CNT_CTRL and by
means of parameter assignment.
Bit
Behavior of the FM 450-1
ENSET_UP set
The counter is only set in the case of up counting
ENSET_DN set
The counter is only set in the case of down counting
ENSET_UP and
ENSET_DN set
Counter is set for up and down counting.
Parameter assignment
Behavior of the FM 450-1
Parameter assignment
"single setting of counter"
The counter is set only at the first rising edge at input 1I2 (2I2).
If the counter is to be set again, you must first set ENSET_UP or
ENSET_DN again. The counter is then set again with the next positive
edge at input 1I2 (2I2).
Parameter assignment
"multiple setting of
counter"
As long as ENSET_UP or/and ENSET_DN are set, the counter will be set
with each rising edge at input 1I2 (2I2).
Note
It is imperative that you set one of the two variables, ENSET_UP or/and ENSET_DN, so that
the relevant counter can be set via input 1I2 (2I2).