Chapter 2 Devices 2.2.11 Counters The characteristics of the 16-bit counter: The function of the counter: Each time the input switches from OFF to ON, the value of the counter increases by one increment. When the value of the counter matches the setting value, the output coil is ON. Users can use either the decimal constant or the value in the data register as the setting value. The 16-bit counter: 1. Setting range: 0~32,767 (The setting values 0 and 1 mean the same thing in that the output contact is ON when the counter counts for the first time.) 2. For the general-purpose counter, the current value of the counter is cleared when there is a power cut.
If the counter is the latched one, the current value of the counter and the state of the contact before the power cut will be retained. The latched counter counts from the current value when the power supply is restored. 3. If users use the instruction MOV or ISPSoft to transmit a value bigger than the setting value to the current value register C0, the contact of the counter C0 will be ON and the current value will become the same as the setting value next time Ч 0.1 is switched from OFF to ON. 4. Users can use either the constant or the value in the register as the setting value of the counter. 5. The setting value of the counter can be a positive or a negative.
If the counter counts up from 32,767, the next current value becomes -32,768. Example: 1. When Ч 0.0 is ON, the instruction RST is executed, the current value of the counter C0 is cleared to zero, and the output contact is reset to OFF. 2-53 Item 16-bit counter Type General type Number C0~C2047 Direction Counting up Setting value 0~32,767 Specification of the setting value The setting value can be either the constant or the value in the data register. Change of the current value The counter stops counting when the value of the counter matches the setting value. Output contact The contact is ON when the value of the counter matches the setting value.
Reset When the instruction RST is executed, the current value is cleared to zero, and the contact is reset of OFF. Action of the contact After the scan is complete, the contact acts.