Siemens FC 105..... HELP!

Hello, I am having such a hard time with this Function and I really hope you folks can help me out. I have read the other posts regarding this block but here is my problem. Everytime i try to enable it by making the logic at EN =1 it faults my PLC. I have the "EN" tied to a regular input with a toggle switch just for troubleshooting. I am using this to scale the value from an anlog input so i have PIW752 at the "IN". I have "HI_LIM" = 5.000000e+001 and "LO_LIM" = 1.000000e+000
I have BIPOLAR tied to another toggle swich input for troubleshooting and i leave the toggle swich = 0. I have nothing at "ENO" there is just a straight line when viewed in ladder. I have "RET_VAL" = MW100 and "OUT" = MD110. First of all are there any problems with the values I have entered? My high and low limit I have just typed in the numbers I have shown I have not stored them in an MD somewhere. What am i missing here? I am pulling my hair out right now and i know there is something so simple i have missed. I am calling this from FB4. Is there some setting somewhere i have missed to allow the use of FC's. I have spent many hours with this before posting so your help would be greatly appreciated. Thank-you

Did you go to Module Information to see what the exact error is? It could be anything: an invalid address, a block not loaded, etc. Let's start there, and then we'll move to the next step.

Ok, I am not in front of the PLC right now but I think the error said something about a block not loaded. What blocks need to be loaded to the PLC in order for this setup to work? You will have to forgive me my strength is with Allen Bradley PLC's and i have never had such problems with SCP. Thank you for your help, it is greatly appreciated.

Hmmm, after reading your post again, it seems like your blocks are properly loaded since you don't get the fault until you enable the EN input. On the other hand, if you are using this same input to call FB4, and you haven't downloaded FB4 to the PLC, then the PLC would certainly fault. Doublecheck that FC105 and FB4 have been downloaded.

Another thing you could check is if PIW752 is a valid address. Look at it in a VAT table and see if you get feedback.

I have checked and i indeed see that PIW 752 is valid. I can see its value increase when i increase the current in my 4-20 ma loop. Can I just insert FC105 in my OB1 or does it have to be called from somewhere special? I seem to remember that the error mentioned something about OB101, could this have something to do with my problem? How can I confirm that all of the blocks I need have actually loaded in to the PLC properly? Thanks again for the help..

If you are looking at the blocks off line and there is no errors, highlight "Blocks" and download everything and overwrite the PLC. My guess is, you didn't download FC105 or the instance DB associated with FB4. I am assuming you are calling FB4 from OB1 and FC105 in FB4. You can call FC105 directly from OB1, eliminating the need for FB4 and it's instance DB.

Hello,
When you are working with the LAD/STL/FBD editor go to Menu PLC -> Module Information, Tab "Diagnostic Buffer" You have to see a message why the plc gave an error. If you post your error message here, we could help you better/more.
About OB101, this is an start up OB. I can't imagine this has anything to do with it.
Maybe you meant OB121, this is an OB for programming errors. So if you use addresses outside the range of the cpu for example, the cpu doesn't go to stop mode. Because of the presence of the OB121. But it will show the SF led. Maybe you have used some memory outside the cpu's range.

Looks like you didn't download FC105 to the PLC. I am not sure, because you didn't post the diagnostic info. Go to the Simatic Mangler and download FC105.

Folks, I got FC 105 to work. Thank you very much for your help. Now i am having problems actually formatting the data for what i need. I searched and found that user GTX is recently in the same boat so i have poked my nose into that post for some help there. Thanks again...