In the S7-200 CPU, the counter for the accumulated number of pulses from the input terminal or internal components sent. It has up counter, down counter and up / down counter 3 types.
Due to limitations counter frequency scan cycle, when the need for high-frequency signal can be counted when a high frequency counter (HSC).
There are two forms of addressing the counter.
● the current value of addressing: 16-bit signed integer stores the accumulated number of pulses.
● Counter-bit addressing: a comparison result based on the current value and the preset value is set or reset. Like timers, both addressing ways to use the same format, namely C + counter number. For example: C0