As the title states, I'm new ... real new ... to the Siemens PLC stuff. I'm a die hard A-B programmer. I've been able to "reverse-engineer" much of the S7 program on a German Machine. All the descriptions & documentation is in German. I've been trying to translate to English. Monitoring the S7 program and poking at the buttons on the MP270, I've been able to document ... in English ... much of the program. I've been able to do a small amount of editing ... ie ... added a stack light for machine status. Nothing safety related or changes to the machine's function. So ... I'm trying ... but I just can't seem to get a grip on the "big picture" of interfacing the MP270 and the S7. I know this is gonna sound stupid, but I have no formal S7 training. I'm not going to start writing S7 code from scratch. I just want to be able to look at, and understand this S7 for maintenance and troubleshooting purposes. Here's an example:
I have Protool to examine the MP270 Application
I have IBH Softec to examine the S7 Program
I'm trying to find the "link" between the F1 key on the MP270 and the address (which I cannot find) in the S7 program.
Protool indicates that the F1 to F6 keys are tag'd "tasteF1_F6"
with Type: WORD, Address: MW230 and Elements: 1, I checked each function key:
F1 uses bit 1
F2 uses bit 0
F3 changes to a different screen
F4 uses bit 3
F5 changes to a different screen
F6 uses bit 5
Now ... in the S7 program I cannot or have not been able to find any relation to address MW230 or even M230, as I've seen this "M" address before in the program, but not "MW".
I guess I'm asking ... just how is this relation made? Shedding a little light on this would ... hopefully ... open up the "ahhhhh, I get it" door, thus making my time spent much more productive. There are still issues like how timer values, numerical values, screen changes and the like are handled, but one small step at a time.
Thanks for your input in advance.
Your humble A-B programmer in a Siemens world,
- Tony
I have Protool to examine the MP270 Application
I have IBH Softec to examine the S7 Program
I'm trying to find the "link" between the F1 key on the MP270 and the address (which I cannot find) in the S7 program.
Protool indicates that the F1 to F6 keys are tag'd "tasteF1_F6"
with Type: WORD, Address: MW230 and Elements: 1, I checked each function key:
F1 uses bit 1
F2 uses bit 0
F3 changes to a different screen
F4 uses bit 3
F5 changes to a different screen
F6 uses bit 5
Now ... in the S7 program I cannot or have not been able to find any relation to address MW230 or even M230, as I've seen this "M" address before in the program, but not "MW".
I guess I'm asking ... just how is this relation made? Shedding a little light on this would ... hopefully ... open up the "ahhhhh, I get it" door, thus making my time spent much more productive. There are still issues like how timer values, numerical values, screen changes and the like are handled, but one small step at a time.
Thanks for your input in advance.
Your humble A-B programmer in a Siemens world,
- Tony