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MAB instruction conversion to its S7 equivalent ?

Created by: alpha786 at: 3/16/2009 6:48 PM (3 Replies)

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3/16/2009 6:48 PM	Rate (0)
alpha786 Posts: 2 Rating: (0)	Hello, I am working on an S5 to S7 conversion project and needed some help in resolving my errors. The following especially since these are repeating a lot: MAB LRW TRW I have a 928 CPU and would be migrating to an S7-CPU 414-2DP.. I have already looked at the 'From S5 to S7 Convert' Manual which identified these as not convertible by the S5-S7 tool. I have also looked at the CPU 928B manual and it explained MAB to me but is there a 'Base Register' concept in S7 CPU's as well ?? Is there an equivalent command to MAB, LRW or TRW in S7 ?? I will be looking at the S7 CPU next for clues but if someone has already gone through this excercise and would like to share their experience, it will be greatly appreciated !! Thanks
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3/16/2009 9:28 PM	Rate (0)
Phantom75 Posts: 2661 Rating: (278)	alpha786 . . .but is there a 'Base Register' concept in S7 CPU's as well ?? Is there an equivalent command to MAB, LRW or TRW in S7 ?? . . . Hi alpha786, The closest to the BR (base address register) in S7 is the AR... There are no equivalent instructions to MAB & LRW/TRW in S7. In S5 these instructions were used to access data operands (for examplebytes in a DB)that had a byte address > 255 using absolute addressing. The data block start address was calculated, the operand offset was added and the data operand was accessed using the BR register with LRW/TRW. In S7 you can directly access data operands with addresses > 255. Hence this kind of manipulation is not necessary. If you understand exactly what the S5 program is doing, you can replace with simple L / T instructions... Regards
Phantom75 Posts: 2661 Rating: (278)
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3/18/2009 3:10 PM	Rate (0)
alpha786 Posts: 2 Rating: (0)	Thanks Phantom75, I will revisit my S5 notes and the program based on this information. Best Regards,
alpha786 Posts: 2 Rating: (0)
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5/16/2018 2:40 PM	Rate (0)
Jen_Moderator Moderator Joined: 6/19/2017 Last visit: 5/30/2023 Posts: 6924 Rating: (137)	New question published by ama00 is split to a separate thread with the subject Transfer RS. Best regards Jen_Moderator
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