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7/3/2014 8:49 AM | |
Posts: 1 Rating: (0) |
Hello, i want to know if is possible, in OB1 to limit tthe minimun cicle time. For example, not smaller than 5ms. Thanks a lot. Juan |
7/3/2014 1:54 PM | |
Joined: 8/27/2010 Last visit: 4/13/2024 Posts: 417 Rating: (37) |
Hi! S7 monitors the maximum scan time, ensuring a maximum response time. The value for the maximum scan time is preset to 150 ms. You can set a new value or you can restart the time monitoring anywhere within your program with SFC43 "RE_TRIGR." If your program exceeds the maximum cycle time for OB1, the operating system calls OB80 (time error OB); if OB80 is not programmed, the CPU changes to the STOP mode. Apart from monitoring the maximum scan time, it is also possible to guarantee a minimum scan time. The operating system will delay the start of a new cycle (writing of the process image output table to the output modules) until the minimum scan time has been reached. Refer to the manuals /70/ and /101/ for the ranges of the parameters "maximum" and "minimum" scan time. You change parameter settings using STEP 7. Hereis information source. Page 1-4. Hope it helps. BTW, what for you need to have cycle time not smaller then 5 ms? //There is another option - cyclic interrupt OB's. For example OB38 hav a fixed time of 10ms. Describe your task more detailed in case of additional questions. |
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