Stop and think for a minute. I explained what the return value from SVC_REQ #16 is.
The PLC scan is a continuous process. It repeats a cycle over and over and over...
The SVC_REQ instruction occurs at the same point in the cycle every time the cycle repeats. You can use the SVC_REQ #16 function to capture the time at each execution of the function. The time between successive executions of the function is equal to the scan time.
Think of it this way. You're driving a race car around a 1 kM track. Your pit crew wants to calculate your average speed for a lap, but their stop watch is broken. They do have a watch that continuously runs. When your car passes a fixed point, a member of your pit crew writes down the time, for example 9:15:12.345. One lap later, when your car passes the same point, they write down the time again, for example 9:15:23.456. The time it took for you to complete the last lap was the difference between 9:15:12.345 and 9:15:23.456 or 11.111 seconds.
Please draw a block how i get it? i am very thankful to u.
Absolutely not! Use your own brain. I've outlined a method for you. The details of how to actually get it done are up to you. If you can't figure it out, then maybe PLC programming isn't what you should be doing. Every time someone simply gives you a completed program, it becomes more likely that whenever you're stuck, you'll ask someone else to do your work rather than figure out a solution yourself.