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11/16/2009 2:05 PM | |
Joined: 1/4/2008 Last visit: 9/2/2024 Posts: 703 Rating: (96) |
Every address in programming is "virtual" - always it's an offset to some part of physical memory. Don't know what you mean by hardware address 0.0 but anyway, if you use the TEMP area, the address is an offset to the beginning of the local data stack part of the system memory. More information about the memory concept ofa PLC you can find for example here or in the CPU specification manual. The bit address in the TEMP area is L x.y but I strongly recommend to use the symbolic representation, i.e. to define the local variable. It can't have an initial value, you have to assign the value before using it. For example good solution for programming is imhodefining the "bTrue" local variable(in TEMP area) as first in each function and in the first network make the logic: AN bTrue S bTrue or ----|/|----(S)----| The "bTrue" variable thenhas always logic state 1 and can be used as auxiliary in the rest of function (of course just for reading), especially in LAD/FBD programmingis useful. You can also usesome memory bitas "global" variable, then you don't have to declare and assignit in each block, just once in programm. Regards Sydney |
Last edited by: Sydney at: 11/16/2009 2:12 PMlanguage correction Last edited by: Sydney at: 11/16/2009 2:11 PMlanguage correction |
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11/17/2009 4:32 AM | |
Posts: 382 Rating: (47) |
I agreed with Sydney use memory bit. you can do this if you want: set = m0.0 //set bipolar 1 or clr =m0.0 //set bipolar 0. with regards, how come |
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