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Everything posted by gruntstripe

  1. S7 200 Comms trouble

    Hello, I recently bought a brand new RS232/PPI Multi-Master cable (6ES7 901-3CB30-0XA0) so that I can play with an S7 200 CPU 226 that I have. Everything was going ok for the first few hours of 'playing' but now I lose comms frequently and recieve various error messages: "THE PPI MULTI-MASTER CABLE WAS DISCONNECTED FROM THE PROFIBUS NETWORK. ANY PREVIOUSLY ESTABLISHED CONNECTION HAS BEEN LOST." I'm not even on a profibus network. "YOU MUST USE THE (RS232/USB) PPI MULTIMASTER CABLE TO COMMUNICATE ON A MULTIMASTER OR ADVANCED PPI NETWORK". This appears sometime when I first try to go online - seems to suggest to me that Step7 Microwin V4 cant actually see the PPI lead. "A CHARACTER-BUFFER OVERRUN HAS OCCURED. THE NEXT CHARACTER IS LOST." "NO CONNECTION TO THE SPECIFIED ADDRESS COULD BE ESTABLISHED. POSSIBLY AN INVALID OR NON EXISTENT ADDRESS." Usually the PPI led on the lead stays on but the Tx and Rx leds extinguish when I get these errors. I've checked my comms settings and they are as per the manual. Unfortunately I have only one PLC and one lead so I cant try other hardware. Any suggestions? PLC or Lead fault? UPDATE\EDIT: I've resolved this.
  2. Cleaning Slip Rings

    Hi, What's the best way to clean dirty slip-rings? Can you use an abrasive paper (what grade?) or is a cleaning solvent (IPA?) better? Should slip-rings be dead smooth and shiny? Thanks in advance. (Sorry - I know it's nothing to do with PLCs)
  3. Monitoring a Specific Function Block

    Hi, Suppose there is a function block that is used to control devices, how can I monitor just once specific instance of that function block? Thanks in advance for any help.
  4. FM350-1 Counter Module

    Hello, Trying to learn to use the FM350-1 counter module. Have an SEW incremental encoder (5V, 1024 ppr) that I spin between my finger and thumb. Encoder is set up correctly and works well, can see the pulses being counted and no fault LED on the FM350 module. Goal is this: Load (M20.3 Load Direct) 0 into DB1.DBD34 Spin the encoder. Compare the actual encoder (counter) value against 1024 When actual counter value = 1024, load 0 back into DB1.DBD34 i.e. reset it to zero. With reference to the code in the pictures below, what I have noticed is this: When I spin the encoder 'quickly' for slightly further than one revolution the counter value does not reset to zero when exactly 1024 pulses have been counted, it can count as high as 1200 or more before the count is reset to zero if the encoder is spun really quickly. It's probably because I'm not using the card interface properly. Reading the FM350 PDF leaves me a bit flummoxed. Any ideas about what I'm doing wrong? Any advice greatly appreciated and thanks in advance for it.
  5. WinCC & OP277 'K' Keys

  6. WinCC & OP277 'K' Keys

    Hello, How can I assign functions / actions etc to the 'K' keys on an OP screen? They are greyed out in WinCC. I'd be very grateful for any help and thanks in advance for any forthcoming.
  7. Reading Inverter Drive Paramaters

    Hi, The topic title explains all really. I have been learning through trial and error how to control an ABB ACS800 drive from an S7 315. Good progress being made, especially because of assistance received from other posters. I can now change a drive parameter (see screenshot) by writing to Process Data Words (PZD) but I want to do more, for example what is shown in the second screenshot below. Don't know how to start coding it though and would like some help. Any help gratefully received. Thanks in advance for any help.
  8. Help Required with S7 STL

    Just wanted to say thanks to you two. Helped me get a better understanding of things. Cheers.
  9. Help Required with S7 STL

    Hi, If somebody could help me here I would be very grateful. I'm attempting to get to grips with STL code and I am making progress slowly, very slowly. With reference to the code (which is used in control / communication of an ABB ACS800 Inverter) in the screenshot: As I understand it, we LOAD PIW [AR1,P#0.0] // in this case PIW = 256 then TRANSFER this word to both #SW and #Stat_Word then LOAD PIW [AR1,P#6.0] // i.e. add 6 bytes to the start address 256 then TRANSFER the contents of this address to #PZD4 NOW I GET STUCK, what does 'A L 1.2' do? It's an AND instruction followed by a LOAD. What does the 1.2 do? I'd be grateful for any help, thanks in advance.
  10. Siemens PCMCIA CP5512 access on Virtual PC

    Hi, It's not possible. You cannot access this hardware item from a virtual pc because virtual pc's only use virtual hardware!
  11. S7-414 to S7-315

    Hello, Hope you are all ok. What is the correct procedure to follow if I wish to transfer a program from a 414 to a 315? Thanks in advance for any help.
  12. S7-414 to S7-315

    Thanks JesperMP, I have converted the program succesfully.
  13. Hi, I had an ABB ACS800 inverter problem yesterday: the drive tripped at start up with fault code 2340 (short circuit). The manual suggested testing both the motor windings and the supply cable. Using my Fluke the windings only measured about 0.1R which is only the meter lead resistance I presume. I couldn't determine if there was definately a short or not - the armature winding tails were large cross section so they probably would measure next to nothing. Basically I'm asking what you would expect such a large motor to read and if it is only a very small reading how could one determine if the windings were short or not? As it happens, and after consulting ABB, the fault turned out to be on the drive electronics so we frigged the parameters to keep it going. Thanks in advance.
  14. 400kw motor winding resistance

    Hi, Thanks for your replies. I'm sorry if I didn't make my original post clear enough. I am familiar with motor testing routines (I'm a maintenance Tech'). The nub of the issue is how to assess if a particular winding on a very large ac motor is short - but not to ground. Most motors I usually deal with are pretty small, maybe just a few kw and if a resistance reading is taken across a winding a descernable result is obtained, say like 10R. So one would have three 10R readings (U1, V1, W1) on a good motor. If a winding is internally shorted the reading would be 0R. But on a very large motor of say 400kw rating the cross sectional area of the winding wires is large and the resisance is extremely small by default, I presume. Thus how can one determine if the winding is internally shorted? I have never had to test a motor this large before. I think gravitar had a good answer.
  15. S7 Lite Licence ?

    Hi, It's free. I've used S7 lite but I don't like it. It's quite different in it's appearance and functionality to proper S7. It seems to run quite slowly aswell but that might just be the pc it was installed on. Still, if you cannot afford to purchase S7 proper it is still an extremely good way to get to grips with S7 programming. Regards.
  16. Hello everyone, If I download a program written for an S7-400 to an S7-300 is there an automatic way to remap i/o when the slot/card positions are different? Thanks in advance for any help. GS
  17. Converting STL to ladder

    Thanks to both of you for your help. It's now done and works fine!
  18. Converting STL to ladder

    Hello, I have tried to translate some STL code to ladder to make it easier for me to understand but I'm not sure I've correctly interpreted the STL code. Could you have a look and tell me if (and probably where) my mistakes are? Sorry for the fuzzy images - haven't figured out how to create nice sharp ones yet. Thanks in advance for any help.
  19. S7-300

    Hi moggie, Thanks for that info' - I didn't know about this functionality. I just tried it on my 315. It didn't work at first because I didn't download the modified hardware configuration. Maybe this is semilogicals' problem.
  20. S7-300

    Hi semilogical, Where does it say this? GS
  21. S7 Lite indirect addressing problem

    Hi, Firstly I hope I've titled this topic properly. If you look at my pics you'll see that when I address directly there is an output but when it's done indirectly there is not. Can't see why, can you pint me to my error? M1.0 definately gets set: but only in the first rung here so my number does not get written to the output: using the discrete inputs only - it works: just for interest, when in parallel the middle M bit does not change: Thanks in advance for any help. P.S. I use S7 Lite and find it to be very sluggish in operation, mainly when it's in monitor mode. Networks take ages to update and this is frustrating when troubleshooting. I use a serial MPI / PC adaptor. Do you think things would speed up if I used a USB type?
  22. S7 Lite indirect addressing problem

    Thanks Groo, I see what you mean. I'm embarrassed, it's so obvious. Still get a bit confused by memory mapping. I've used different addresses - 'far apart' and now it works. Cheers.
  23. Really Basic Data Logic Question

    Hi, My question is in the screenshot below. It's from Step7 lite. I understand that if you move, for example, a byte to a word the result will be padded out with zeros'. Or a word to a byte will be truncated. But I don't understand what is happening here. Thanks for any help.
  24. Really Basic Data Logic Question

    Hi Steve, Yes I can follow what you're stating but I can't see why it is so. I would have thought MW0 = MB0 & MB1, MW1 = MB2 & MB3 and so on. Regards, gs
  25. Step 7 Lite: 7 seg display instruction.

    Hello, Thanks for your replies. I'm a bit thick - how do I make this FC work? Thanks in advance, gs