Siemens PLC Learning note 10-(counter)

The s7-300/400 counter typically accounts for two bytes and is 16 bits. The CPU can use a maximum of 64~512 counters with the counter address number c0~c511

1.s_cud (plus and minus counter)

Add and subtract counter waveform diagram:

2.S_CU (plus counter)

3.S_CD (minus counter)

4. Three kinds of counters corresponding to the coil representation

1) Basic Coil instruction

2) Implementation of the plus count instruction

3) Reduce the count of instructions to achieve:

4) The addition and subtraction of the Count command to achieve:

5. Small example of counter application

The following program is implemented: When the button is pressed 3 This, the output high level; When pressed 7 times, the output low level

Siemens PLC Learning note 10-(counter)