Chapter 6 Applied Instructions Symbol S 1 ： Counter value S 2 ： Setting value for the cycle time D ： Number of pulses from the previous scan cycle Explanation 1. This instruction requires that you use S 1 with the DCNT instruction (API 1004) to enable the high speed counter with 6_ counter numbers above HC200 (including HC200). 2. The time units for S 2 (the setting value for the cycle time) are millisecond (ms). The setting must be between 10–1000. When the value is out of range, the PLC executes the instruction with S 2 at the minimum value or the maximum value and there are no error messages. 3.
When the count reaches the setting value in S 2 , this instruction stores the number of pulses in the device specified by D , and is not affected by the PLC scan cycle. 4. This instruction has no limitation when editing, but it only allows eight sets of speed detection instructions to run simultaneously. The system ignores the ninth set of the speed detection instruction and there are no error messages. When executing this instruction, the setting values for the operand are recorded, and during the execution of this instruction, you cannot edit the parameters.
6-291 API Instruction code Operand Function 1008 D SPD S1, S2, D Detecting speed Device X Y M S T C HC D FR SM SR E K 16# “$” F S1 S2 D BOOL WORD DWORD LWORD UINT INT DINT LINT REAL LREAL TMR CNT STRING Data type S1 S2 D Pulse instruction 16-bit instruction 32-bit instruction － - ES3