VFD Guy

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About VFD Guy

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  1. I have ran into this many times. I’m a big fan of divide and conquer. 1st. Figure out if the drive is doing what you’re commanding. Compare the commanded reference with output frequency. If they don’t match, then you’ve hit a limit. Look at the at limit parameter to see what’s going on. The 750 will reduce the output frequency to reduce the current. You can follow the block diagrams in the manual to see which regular is at a limit
  2. Data Types for MAM instruction

    @panic mode great explanation. Far better than I could do
  3. Moving Local Tags

    Joe E’s Method is good. Doing a control f and replace all would be much quicker. As long as you and ensure the tags being replaced are the ones you want
  4. Data Types for MAM instruction

    Copying a real to a dint isn’t gibberish. It’s an IEEE 754 conversion. I agree with you on the rounding error from float to dint when you mix data types. However a copy will convert the data type. I’ve had to do this for drives on devicenet. Get the reference I want as a real, copy to a DINT, send the DINT to the drive, the drive (750 in this case) would convert back to a real. You can look on knowledgebase. Many technotes on it. Or just look up the IEEE conversion. I probably went on a tangent from your question but just wanted to say I’ve had to convert before. In your specific case, if you put a DINT tag into a tag looking for a real, I believe it just adds .00 to it. Devicelogix does that. And vice versa, I believe logix would truncate a real if put directly into a dint 
  5. Data Types for MAM instruction

    Moving a data type into a different one will treat it as such. So a DINT 60 will be treated as 60.0 real. However. If you do a copy COP command, logix will do an IEEE 754 conversion from float to dint or vice versa
  6. AB Studio 5000 Lite

    What version of studio? Updating the AOP might help
  7. Communication

    @ElectronGuru  you’re correct that the speed reference the drive is pointing to probably can’t be changed while the drive is running but by understanding the io image, you can ‘change’ the speed ref on the fly by writing to the logic command to point to a new reference.    I agree that ample testing should be done before changing a live system. Sounds risky in any manner
  8. Fault Reset on powerflex

    @ElectronGuru a pf70 doesn’t always have to be the same input to clear faults and stop. There is a clear fault mask to prevent the clear fault. Stops can’t be masked I believe you’re asking if only a clear fault can be sent via comms. Yes it can. See the logic command word. If you want to mimic a stop button key being pressed, then that may take two network signals depending on how your stop button and masks are setup as
  9. AB Studio 5000 Lite

    If you email radrivessupport@ra.rockwell.com, they usually respond in 24 hrs. Worth a shot
  10. Communication

    @ElectronGuru the second bullet point would stop the process. It sounds like this isn’t acceptable. Would it be easier to send a reference from the micrologix to the compact logix then do an online edit to redirect the data from the micrologix? 
  11. CompactLogix Point I/O Module Limits

    It’s been a while since I looked but Rockwell had an enet resource tool to build your system and test if the hardware would support the number of connections. Look on their IA site
  12. Communication

    If you have some free outputs on the drive, you can make a clever speed select with parameter control on a DO wired to a DI to choose a speed select of parameter 38. I’m not completely understanding what needs to be done. An MSG is pretty simple if you’re sending a new reference 
  13. Fault Reset on powerflex

    The red stop key is a stop and clear fault. These signals are separated into 2 bits over the logic command
  14. All powerflex 70s can use 20 him -xx. Even new A6 hims. Blank face is just a blank plate that comes with the drive as a place holder. If the him is not backlit then the power from the mcb is not powering the him. Are you using port 1 on the drive or a remote him? If the him is backlit but not logging in, make sure it it at the latest fw or flash the 70 back to the one replaced
  15. 1756-EN2T Anomalies

    Other than the obvious of divide and conquer through the network, there may be an issue with the new Mac and the ip compared to what the switch has in its Mac table. Try the en2t in the same slot with a new IP. This would tell me there's a mac issue in the switch.