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  1. CanadianTaff

    Unity XL Pro Freeze Value

    Actually I see the issue with your original code, no tag on the MOVE output, therefore nothing to remember the value sent through.
  2. CanadianTaff

    Unity XL Pro Freeze Value

    I can't see an issue with the logic in my mind it should work, it is a bit complicated though. I do something similar with logic which freezes the last good value when an analog input fails, all you need is the OR and SEL instructions. Delete the second OR, MOVE and R_TRIG. Remove the Negate...
  3. CanadianTaff

    Counting pulses to display rotation speed

    you can also buy a fairly cheap digital to analog converter and receive a 4-20mA signal.
  4. CanadianTaff

    Siemens HIM with LOGO 0ba7 PLC WinCC

    First thing, the LOGO is not a PLC, its an intelligent relay. The problem you are having I imagine, is simply that the LOGO will update its input status and over-write anything that you may send from the HMI.
  5. CanadianTaff

    Start stop using one push button

    Forget what IRstuff says about bad practice, its actually quite common practice and nothing wrong with it, it has its uses. The easiest 2 line code is as follows. Pushbutton Trigger ---[P]-----------( )--- Trigger coil coil --] [---]/[--+---( )---...
  6. CanadianTaff

    step 7 trial win 7

    Siemens do give 'free' trial period licenses for the full version too. I believe they are 14 day.
  7. CanadianTaff

    Siemens S7 M0.0

    Bit of the Clock Memory Byte Period Duration (s) Frequency (Hz) 7 2.0 0.5 6 1.6 0.625 5 1.0 1 4 0.8 1.25 3...
  8. CanadianTaff

    Siemens S7 M0.0

    My bet it is used as the clock pulse, MB0 is the default for this and enabled in the CPU properties in the hardware profile. Each bit from M0.0 through to M0.7 will switch at a different frequency. Bit of the Clock Memory Byte 7 6 5 4 3 2 1 0 Period Duration (s) 2.0 1.6 1.0 0.8 0.5 0.4 0.2 0.1...
  9. CanadianTaff

    Siemens S7 M0.0

    Its an internal memory bit. M 0.0 is the least significant bit of the byte MB0
  10. CanadianTaff

    Siemens to AB conversion

    OK, so your saying for your local support and spares its better, no problems with that, Thought you mean't it could do things that Siemens cannot. The better PLC is obviously personal preference (Siemens for me), they are both good PLC's and both equally able in automotive applications.
  11. CanadianTaff

    Siemens to AB conversion

    'for our applications (Automotive) works better' bizzare thing to say.
  12. CanadianTaff

    S7 PLC and VFD

    Just to make a point about number 2. You would not size any overload protection for the motor, the overload should be prior to the VFD and it will be to protect the VFD, therefore should be sized for the VFD. As mentioned by 2B2, the VFD will protect the motor. You would only need motor...
  13. CanadianTaff

    Sorting conveyor

    One thing I forgot to mention. Any sensors that detect the object en route should be use to re-synchronise the objects position in the tracking zone.
  14. CanadianTaff

    Sorting conveyor

    Controlsdude, not sure if those last comments are about what I wrote or not, but if so then I will try to respond. "so you feed a box on how when the main sorter is at full speed?" The prior conveyor would have a PEC that is used to stop the box if the sorting conveyor is not running (or about...
  15. CanadianTaff

    Sorting conveyor

    'One thing to consider is what to do if things get out of sequence. I have seen systems where it is a real mess if a box falls off the conveyor. You need away to edit or clear your FIFO' That is where the 'missing' box logic comes in, if not detected in the expected window then clear the data...
  16. CanadianTaff

    Sorting conveyor

    Some additional. (I'm presuming one long conveyor). If money is a problem, Instead of an encoder you can use a proximity switch and a flag attachd to a non driven roller, best opposite end to where motor gearbox is. I would ensure a brake motor is on the prior conveyor so you can stop-start to...
  17. CanadianTaff

    Auto-transformer - Earth Leakage Problem

    Thanks for replies, we're tallking with the manufacturer about wiring as Delta now. Just as a footnote though, we're dropping 100V, from 1100 to 1000, not dropping to 100V. Its only a small amount, but apparently a big difference in that at 1000V it can be catagorised as a low voltage machine.
  18. CanadianTaff

    Auto-transformer - Earth Leakage Problem

    We have a piece of equipment which was designed to be supplied by 1000VAC, the customer informed us late on that the supply would be 1100VAC. As a solution an auto-transformer was used to drop the supply to the designed level. Now when the power is applied the main breaker trips due to the...
  19. CanadianTaff

    Difficulty in understanding PLC 5 Logic

    The data is made up of 16 bits, the AND instructions is transferring the low 4 bits (a number between 0-15) into D56:16 and then transfers the high 12 bits into N7:32, which I imagine is just a temporary storage. The final divide by 16, is simply shifting the bits to the right before storing...
  20. CanadianTaff

    Step 7 forcing/modifying values

    You cannot force internal memory bits with Siemens. The program can revert it. You can force I/O through the force table.

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