Siemens simatic s7-400 FM 450-1, Руководство пользователя, Страница: 87 / 130

Modes, settings, parameters and commands
8.12 Initiating a process interrupt
Counter module FM 450-1
Manual, 02/2014, A5E03648739-02
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Multiple setting of the counter with input 1I2 (2I2)
The following figure shows the multiple setting of counter 1with input 1I2. The situation is
analogous for counter 2 with input 2I2. In the case represented here, only ENSET_UP is set,
i.e., the counter is set during up counting.
The relevant counter is set with the first rising edge at input 1I2, as long as ENSET_UP is
set. When you reset ENSET_UP you cannot set the counter with input 1I2. Only after you
have set ENSET_UP again will the next positive edge at input 1I2 result in the setting of the
counter.
Figure 8-8 Multiple setting of counter 1 with input 1I2
Setting the counter with the zero mark
If you assign the parameters for setting a counter with the zero mark of the encoder, the
relevant counter is set with the rising edge of the zero mark.
Setting is only performed if input 1I2 (2I2) of the relevant counter is set at the time of the
rising edge of the zero mark.
With the ENSET_UP and ENSET_DN variable is the DB of the FC CNT_CTRL and by
assigning parameters, you specify the behavior of the respective FM 450-1 counter in the
case of a rising edge of the zero mark.
Bit Behavior of the FM 450-1 counter
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.