6. Function blocks6.1 Manufacturer function blocks6.1.2.4 CI - Incremental counterGeneral informationeasyE4 base devices provide 2 high-speed incremental encodercounters, CI01 through CI02. The high-speed up and down coun-ters are internally hardwired with the digital inputs I01...I02 orI03...I04 and operate independently of the cycle time.Operating principleIncremental counters interpret rising and falling edges in order to identify the count dir-ection. The count will be in the direction of the rising and falling edges.The counter wiring must observe the following digital device input assignment:I01 Counter input for the counter CI01 channel A.I02 Counter input for counter CI01 channel BI03 Counter input for counter CI02 channel AI04 Counter input for counter CI02 channel BThe contacts will switch according to the actual value. The appropriate function blockoutputs switch according to the actual value determined. The counter relays enable apreset start value to be defined at the SV input.Only square wave signals are permissible.The mark-to-space ratio is 1:1.The signals of channels A and B must be offset by 90°. Otherwise the count directioncannot be determined.Positive count directionIf the rising edge at channel A is detected before the rising edge at channel B, thecounter will count up. This means that the counter will be incremented by 1 after thereis a rising edge at channel A followed by a rising edge at channel B. The same applies tothe falling edges in sequence at channel A and channel B. The counter relay's result willbe incremented and output at output QV.Figure 134: CI function block counting up; QV=QV+4easyE4 11/18 MN050009 EN www.eaton.com 237
