Money4Nothing

MrPLC Member
  • Content count

    58
  • Joined

  • Last visited

Community Reputation

0 Neutral

About Money4Nothing

  • Rank
    Sparky

Profile Information

  • Country United States
  1. Does whining alot work? If so, I think I'm just the man for the job $
  2. Time for my NOT training

    My mistake, I got a little ahead of myself. You are right. If you want the negative of a number in two's compliment from 1 to 16 (in decimal), subtract 1 and do a Bitwise NOT. $
  3. Stupid question, PB and scantimes

    Gravitar gave you the right answer. If you One-Shot the pushbutton, it doesn't matter how long the button is held down, nothing will happen until its pushed again. The One-Shot won't be reset until the rung-in condition goes false, e.g. the button is let go. Your only problem then is sequencing what happens when the button is pushed each time. $
  4. Time for my NOT training

    Alaric is correct. To find the binary negative of a number in two's complement form that is n bits long, you subtract it from 2^n. So if you have a 15 bit number, and you want its negative, subtract it from 1000 0000 0000 0000. The twos compliment of binary 0000 through 1111 can be found by doing a bitwise NOT, but beyond that you should use proper binary arithmetic. $
  5. Allen Bradley 1794-ADN

    If your I/O status and Mod/Net status LEDs are not on, then you have a problem with your connection to the network. Check the voltage of the device net power at the module. Make sure the polarity and level are right. Make sure your CAN lines are not crossed. You may have a problem in your tap or drop. Check the connections very carefully. If all that checks out, you probably have a faulty module, and you'll need to replace it or get tech support form Allen Bradley. Try to swap that module with another one in your network, and see if you can connect. $
  6. Thx, I learned something new 1 million reputation points for you. $
  7. Web Hosting

    I've found that the case of web pages is similar to PLC programs in that Simpler is Better Eye candy will only get you so far....simple, intuitive, and functional contect is where the quality is. $
  8. Allen Bradley 1794-ADN

    I had this exact same thing happen to me about a week ago. I removed the ADN from the scan list. Then I disconnected the DeviceNet plug, recycled module supply power, reset the node address, and reconnected the DeviceNet plug....in that order. Then I added it back to the scan list and was up and running with no problems. Also, I was using 125kb or autobaud on everything on my network. $
  9. You cannot split an RS232 signal, its 1 to 1. If the HMI is connected to the serial port of the PLC, and it's using RS232 communication, you can't do anything unfortunately. If there is no other free port on the plc you would have to reconfigured the PLC port to use DH485 DF1, then you can have multiple nodes. You would have to use DH485 drivers for the HMI and your PC serial port. I've never used a splitter or anything similar for wiring an RS485 bus, i've always just wired the individual conductors to custom db9 connectors. Correct me if i'm wrong. $
  10. Series wiring

    Determine the input impedance and on-current level of your PLC input. Then take the prox switch voltage output and subtract the LED drop. V=IR will let you know if you'll have enough voltage to power your LED and still detect the signal level. $
  11. Hello guys, gals

    I got away from Omron when I discovered that I liked AB's communication with distributed I/O better. On a side note, for small systems, nothing beats the Toshiba T1-enhanced. For $150 with free software you won't find more processing power anywhere in the world. Plenty of instructions, I/O and comm expansion. Easy to program. Much more functional than those "budget" PLC like EZ. $
  12. RSView Studio

    Exactly what object did you create? Did you make a Numeric Display object, a String Display object, or a Text Display object? $
  13. RVIEW SE

    Create a local message display. In the connections tab of the local message display, create an expression that is equal to 1 when pushbutton 1 is pressed, 2 when pushbutton 2 is pressed, etc. You can either use a numeric tag from the PLC or use If, Then, Else. Create a new local message. For Trigger Value 1, enter Data1...etc.etc Assign your local message display to point to the new local message, in the General tab of the local message display properties. Use RSView Studio help files to search for "local message" for more info. $
  14. Comments ?

    Obviously understanding the process that is being controlled is the #1 way to understand the controller code. In Allen-Bradley's new Logix5000, tag names help with commenting. As a programmer, the best way to help future readers of your code is to make it efficient and logical. I have seen too many programs where the programmer seemed like he was trying to invent a jigsaw puzzle. And I have seen others that were so beautifully written that I didn't need the comments at all to understand exactly what was going on. Structure the code into groups by function, priority, and other criteria that is logical for the process. Don't overload your rungs, but don't spread out your instructions too much either. Group your I/O into sequencial, logical groups. Keep your communication code and mapping seperate from I/O and computation. A great exercise is to read your own code without comments, and then let a colleague do so as well. I always read my own code without comments to make sure that I can at least understand myself. Good luck. $
  15. Programming Machinery From Scratch

    The way I learned to program from scratch: Took a system. Learned about it. Programmed it from scratch. Fixed mistakes and learned as I went along. It wasn't really too difficult. $