2/22/2014 3:25 PM | |
Joined: 9/27/2006 Last visit: 4/30/2024 Posts: 12257 Rating: (2666) |
Hello kiran; A PLC scan cycle includes reading inputs to the input image table, writing output valuesfrom the output image table, reading and writing peripheral addresses for analogs and communications,processing interrupts and executing all the active logic in your program; so it will never be exactly the same in every cycle. See how it is described in the following manual: SIMATIC Programming with STEP 7 V5.5, ch. 4,2 Scan Cycle Time The scan cycle time is the time required by the operating system to run the cyclic program and all the program sections that interrupt the cycle (for example, executing other organization blocks) and system activities (for example, updating the process image). This time is monitored. The scan cycle time (TC) is not the same in every cycle… Examine the time diagrams that accompany this paragraph for a detailed explanation. Hope this helps, Daniel Chartier |
2/22/2014 5:12 PM | |
Posts: 8946 Rating: (999) |
Usually, scantimes are given as aproximate value for bool- and arithmetik operations (as integer and real) in ms/kb or µs/kb. |
9/24/2014 1:54 PM | |
Joined: 9/3/2014 Last visit: 3/13/2019 Posts: 4774 Rating: (123) |
New question published byshivendra jai...is split to a separate thread with the subjects7-200 input delay 6.40 ms to 0.20ms (2). Best regards Min_Moderator |
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