- #Siemens simatic s7 300 plc manual#
- #Siemens simatic s7 300 plc upgrade#
- #Siemens simatic s7 300 plc code#
But there's one thing that is sure : it can do many many things others plc just can't and at a faster speed. I don't like working on siemens neither, particularly on hardware configuration, very very complicated compared the AB (almost) plug'n'play. ie any other system using a 1_complement negative instead of the usual 2-complement, or floatting nums other than IEE 754, you can get these value from an exotic system and be able to treat them. You can store in a word whatever you want the way you want, it is a way to create your own 16 bits type that many other plc don't allow unless you create an array ie logix: BOOL. An integer is supposed to be a value, a word is not, type indicates the UC the treatement to perform if so, for the same reason an unsigned integer is not an integer (ie FFFF-1). It is particarly good at coordinating many different systems : I've seen an exotic 9 pin communication protocol perfectly treated by an S400 as it was possible to emulate a com kernel. ie: changing only the PLC and still be able to manage the ageless bcd coding wheel and others last century's devices.
#Siemens simatic s7 300 plc upgrade#
On the other hand, keeping the 'old way to do it' was a commercial guarantee for siemens that their PLC would be chosen for cheap upgrade of old machinery / factories.
#Siemens simatic s7 300 plc manual#
Same as automatic / manual shift in a car, the first is easy, but the second has control.
#Siemens simatic s7 300 plc code#
But for structured text based code, we depend on the compiler quality that could generate garbage code that slows the UC down with useless / not optimized commands. Hi, rswolff : Wether you like it or not, the low-level abilities of the siemens makes it much more powerful and faster than any other that would be compiler dependent (ie : logix) though, i can't disagree, it can be a pain in the booty sometimes, LIST code is hard to read, to maintain and takes time to be deciphered. so why does every single Siemens 'programmer' I know tell me how wonderful STL is over ladder? I stopped (for the most part) programming in assembler when I stopped using my Apple 2c (6502) and my Radio Shack (z80). And we developed higher level languages (C, Basic, Pascal, etc.) because working in assembler was, well, crude and cumbersome. When are there other types of numbers not used anywhere else in the known planetary systems? SIEMENS!!!! You learn that when you need a preset for a timer.a 16bit WORD is not the same as a 16bit INTEGER and neither are the same as a 16bit TIME!!!! and what kind of a modern processor still uses BCD? SIEMENS!!! of course!! Buy a SIEMENS and get 50 year old technology masquerading as something s actually less. when is a 16bit word not a 16bit integer? it is EVERYWHERE in the a SIEMENS!!!!!! (try doing a MOVE from one to the other).yes it can be s just annoying. Or you could simply get a baseball bat and smash the dang thing (the Siemens PLC) to smithereens. Yes you need to do a bit of reading, not just on the data areas but the programming structure. There are also data blocks, which is used to group stored data into a common area. Its always best to assign names to these in the variable area at the start of the block. Within each block you also have Temp memory, where you can assign names to throw away memory, ie store a result which is part way through logic to be used further in the same logic block and will be re assesed from scratch next scan (these can be termed as scratch flags). M flags are internal memory addresses where you may want to store results of logic that you need the next scan. For outputs you have Q, QW and PQW, similar to the inputs. WEhen you create your cards you tell it what addresses to use for the cards. When you create your hardware profile, you create your racks and cards. At the beginning of a scan the periphery values are transferred to the image table and the image table is used in the program for digital addresses, analogues generally use the periphery data. The I/IW Inputs are all an image of the periphery, they are referred to as an image table.
PIW = Periphery IW, this is the actual real time value of an input word. I = digital inputs, example I 10.0 IW = Analogue inputs, such as IW250, although you would usually address an analogue as PIW in a standard PLC.
You have a number of different types of data and these have a basic level of a Byte (8 bits).