6/3/2009 5:17 AM | |
Posts: 60 Rating: (2) |
Dear all what is the means of bs121,bs122,bs123, which manul show the instruction of BS and how can i convert the l bs121,the code to S7 program ? eric |
6/3/2009 9:43 AM | |
Joined: 10/7/2005 Last visit: 11/12/2024 Posts: 3027 Rating: (1057) |
Hello again hefeng_05 am I correct in assuming that you use a 115U S5? If so, BS121,122 & 123 simply contain the CPU cycle timeas per abstract of chapter 2.6 from the 115U system manualbelow (you can download the manual here http://support.automation.siemens.com/WW/view/en/1085937): 2.6.1 Measuring the Scan Time The scan time is measured by the CPU and stored in the system data area. You can access the current, the minimum and the maximum scan time in the control program at any time.The resolution of the scan time is one millisecond, and the range of scan time values extends from 0 to 32,767 (=7FFFH) milliseconds. At the end of a scan cycle, after it has updated the process output image (PIQ) and the interprocessor communication flags, the operating system stores the scan time, i.e.: • Current scan time inRS 121 Please also note the following:Don't get confused by the manual using SD121 (System data) in some places and RS121 in other places, these are all the same and this just due to some "poor" translations (and to make matters even more confusing, the Germanmnemonic for these is "BS"). If you want to retain this feature in Step7, you'll get the same three cycle time values supplied as part ofOB1's TEMP variables as shown below: - OB1_PREV_CYCLERun time of previous scan (ms) - OB1_MIN_CYCLEMinimum cycle time (ms) since the last startup - OB1_MAX_CYCLEMaximum cycle time (ms) since the last startup I trust this helps. Cheers Fritz |
Cheers |
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This contribution was helpful to2 thankful Users |
6/4/2009 3:28 AM | |
Posts: 60 Rating: (2) |
Thank you very much for fritz |
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