cwsocr
Member
Hello all. I am new to this forum/site, and have already seen that a lot of helpful, knowledgable individuals contribute to this forum. I am fairly new to the Siemens STEP7 world, and am currently working on a job that I must revamp. The original job was done in Germany, and the entire S7 program has been developed in uncommented STL, while all titles/parameters are in German. I am years removed from any work with assembly language, and I am running into questions while deciphering the logic and the registry handling.
I was hoping that someone could give me a good resource that could help me understand the way the internal registers work, as well as register indirect addressing within S7. I've found a lot of information within the Siemens manuals, as well as online. However, I have not been able to find anything that explains both in depth. Perhaps, and it is likely, I have not searched using the correct keywords.
I would like to understand the accumulators (ACCU1, ACCU2) and how their memory allocations (ACCU1-L, ACCU1-L-L, ACCU1-L-H, etc) are effected by specific instructions, what they are, and the differences between the nomenclatures.
Also, I'd like to read up on how the Address Registers for Register Indirect Addressing/Pointers in the form of [AR1,P#0.0] work. One of the things that I have seen is the use of SLW/SLD instruction when using this type of addressing, but I do not know why this must be used.
Thank you in advance for any information you can provide or give to me. I really need to understand these two aspects as I try to decipher this software. I really appreciate it.
CPU: CPU315: 315-1AF03-0AB0
I was hoping that someone could give me a good resource that could help me understand the way the internal registers work, as well as register indirect addressing within S7. I've found a lot of information within the Siemens manuals, as well as online. However, I have not been able to find anything that explains both in depth. Perhaps, and it is likely, I have not searched using the correct keywords.
I would like to understand the accumulators (ACCU1, ACCU2) and how their memory allocations (ACCU1-L, ACCU1-L-L, ACCU1-L-H, etc) are effected by specific instructions, what they are, and the differences between the nomenclatures.
Also, I'd like to read up on how the Address Registers for Register Indirect Addressing/Pointers in the form of [AR1,P#0.0] work. One of the things that I have seen is the use of SLW/SLD instruction when using this type of addressing, but I do not know why this must be used.
Thank you in advance for any information you can provide or give to me. I really need to understand these two aspects as I try to decipher this software. I really appreciate it.
CPU: CPU315: 315-1AF03-0AB0
