ThePLCPeon

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About ThePLCPeon

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  1. Running a FRD700 Drive Over Comms

    Thank you very much Gambit, much appreciated.
  2. Running a FRD700 Drive Over Comms

    Hello, I am going to be doing a job using an FX3G-24M PLC and an FRD700 invertor. I am wondeirng how I send a setpoint and run/stop signal to this invertor? What bits of what words to I need to toggle to run this invertor. I have experience with Mitsi software and plcs but i have never had to setup a drive with comms. I am also using an FX3U4AD and a FX3U4DA. I will being using structured ladder as it is easier to break up the code in this manner, any advice or help on setting up the analogue cards would be helpful too, Its been a while but I remember it being a bit awkrard having to use head addresses and extracting data from buffer memoery etc. Thanks in advance for any help givien.
  3. FX3U CPU comparing floats

    yes, will this work when using floats/reals? Also how does it read the instruction? For example i would read [D< D100 D102] as if D100 is less than D102 then the instruction would be true. Is that correct? Thanks for the help.
  4. FX3U CPU comparing floats

    Hello, I am currently using some floats/reas in my code that i would like to compare such as >, <, >=, <=, and = . The instruction I am using at the moment is [DECMP DX DY MZ] which dos work. I find this to be harder to read and follow than using [> DX DY]. The m bit MZ  will go high when  DY < DX MZ+1 will go high when DY = DX and MZ+2 will go high when DY > DX. So my question is this; Is there an inctruction I can use to compare floats with simply one instruction ie the [> DX DY] format? Or am I limited to using the DECMP when working with floats? Thanks.
  5. ASCII Comms issue

    Yep I thought that was the case, this was a big help thanks again.
  6. ASCII Comms issue

    Hello again, I have made changes to the code to what I think is a more logical sequence of events. My only question now is, I want to wait until the buffer is clear before I perform my write instruction again. I am not sure how to do this, Is the a clear buffer "done bit" I can use and will that work? Or should I check the buffer for characters again before I go back to my write instruction. Here is a picutre of the current structure. Also just FYI the timer T4:14 Is flip flopping with another 1s timer so atm the write instruction will be perforemed every 2s regardless of anything else.  
  7. ASCII Comms issue

    Thank you for your help I will give this a try!
  8. ASCII Comms issue

    Hello, I am having a recurring issue with a system using ascii to tranmist weighing data. The system will work but every few days there will be a random erroneous value input as the current weight reading. The plc then seems to "freeze" and can only be reset by going online and clearing the erroneous readings from the strings as well a the string reply from the terminal. This is all new to me and I think the problem lies with the structure of "write, read and extract" I think I may be picking up part of the reply string I do not want. The following is the reply string I recieved "   0.0    27.0kg     1   54732>^M^J<000010-01-0007:08   01    2  " what this should be is " <000010-01-0007:08   01    2     0.0    27.0kg     1   54732>^M^J " The strign seems to have been split in two, this is a problem as to extract the weight I am counting "x" characters along the string and then extracting what i need. I need that string to be sent unfragmented as I think this is my problem. I have a attached an image for the current instructions I am using to receive the string, I write a command to the terminal, check the buffer and the read in the string. I then extract data from the string. Any help is greatly appreciated.    
  9. FX PLC Multiple ladders possible?

    Thanks for the reply, it was in simple mode. I have changed the project type now to allow multiple ladders but when I compile i get error F1028. It doesen't seem to like the D7999+. Now i know you can change the range under tools and then device/label automatic setting but you can only go up to 7999 on the d registers. What changes do I need to do to be able to compile this? Would really like to be able to make multiple ladders if i am able to but it might just be less hassle to just work with what i have.
  10. FX PLC Multiple ladders possible?

    Hello there, I am doing some changes to an existing program and found that it is currently just one huge ladder of 5000+ rungs. I seem to be unable to create a new ladder to split up the code I will be writing. My question is, is it possible to have multiple ladders as you can have in siemens and allen bradley? Am I restricted to the one ladder? It is an fx series plc and i am using gx works2. Thanks.
  11. Hello I am trying to set up an inverter fr 800 to work in PLC mode, I know how to get it into this mode but when I try to change the parameter P414 it gives me "er 4" this error means that their is a parameter write error. Is there some other parameter that may be preventing me from changing this one? Thanks in advance to all responses. EDIT: Just after writing this i have solvd the problem, parameter 77 was set to 0 allowing writing ONLY when the invertor is in stop. Changing this to 2 allows changes at any time which allowed me tro change what i needed. I will leave this here in case it helps anyone else in the future.
  12. ASCII to FLOAT Extract

    Micro Logix 1400 using rs logix 500 pro
  13. ASCII to FLOAT Extract

    Hello, I would like to know if there is a simple way to convert an ascii string of say "1500.7" into a float? I know I can use the ascii to int function and convert the first 4 characters which would give me 1500 as an integer. I was hoping I could just get 1500.7 straight into a float.  My current method of doing this is to extract 1500 into an int and then extract the 7 into an int seperatley, I then divide the 7 portion of the number by 10 and add it to the 1500 to get my actual value. Any help is appreciated, thanks.
  14. ASCII to INT conversion

    Hello, if I am receiving an ASCII string of for example "12345" With each number being an ASCII char, how do I convert these to an integer but maintaining the numeric value of "12345". Lets say I receive 500 from a weighing terminal in ASCII form and I want to use that 500 and mov it into an integer or float do I need to do the ASCII to integer conversion function? Thanks.    
  15. COM port sending data

    Not entirely sure what you are trying to do here but this is what I think you are saying. Are you trying to receive information via the 9 pin com port on the ML 1400 or are you wanting to write information to another device by sending it out through this com port? What device are you trying to write to?