Chapter 6 Applied Instructions Symbol D : The time measurement result Explanation 1. The IETS instruction need be used with the API1013 IETE instruction together in order to measure the time for the execution of the instruction in a PLC program which is specified to execute. The unit for the measured time is 1us. 2. When the IETS instruction is enabled, the timing starts immediately until the IETE instruction is also executed. The measurement result is stored in D device. 6_ 3. Minimum and maximum time measurement results are 0us and 32767us respectively.
After the IETS instruction is enabled, the PLC will automatically finish the time measurement and store the measurement result in D device if no IETE instruction has been scanned and the PLC program scanning reaches the END instruction. 4. For the instructions IETS and IETE, there is no limit to how many of them are written in the program. But only one set of IETS and IETE can be enabled every time the scan is executed. If IETS is enabled repeatedly for measuring time, the timing of enabling the last IETS instruction is taken as the start of the time measurement.
On the contrary, if the execution of multiple IETE instructions is completely finished, the PLC will see the point when the first IETE instruction is disabled as the end point when the time measurement is finished. 5. The IETS instruction is usually used to measure the running time of a PLC program such as interrupt service program function blocks and etc. Since PLC’s time-measurement resource will be occupied as the time measurement function is enabled, we suggest the two instructions should be removed after the measuring is completed in order to avoid occupying the PLC resource during the normal execution.
6-301 API Instruction Operand Description 1012 IETS P D The start of the instruction execution time measurement Device X Y M S T C HC D FR SM SR E K 16# “$” F D BOOL WORD DWORD LWORD UINT INT DINT LINT REAL LREAL TMR CNT STRING Data type D Pulse Instruction 16-bit instruction 32-bit instruction ES3 ES3 －