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About graemeian

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  • Birthday 11/04/68

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  • Gender Male
  • Location Durham, North Carolina
  • Country United States
  • Interests PLCs, robotics, building things beyond my skill set.

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  1. Bits on Contactor

    I had mentioned in my initial question, "I can use the counter as a contact to close when it reaches zero. " I assume that one can only use a contact as follows: [P_1s] ----------------------------------------------------------------------------------------------------------------------------------------------------(Counter7) [Counter7]--------------------------------------------------------------------------------------------------------------------------------------------------(A switch would change when Counter7=0) and not something like... [Counter7, bit#3]---------------------------------------------------------------------------------------------(A switch would only follow the status of bit#3) Is that correct?        
  2. Bits on Contactor

    I use ladder logic in its most simple form. In ladder logic on the left, I have contacts(ANDs and ORs configuration). They are either switches, logic results of functions or switches, or canned strobing On the right, I have all types of functions, timers, keeps, counters, etc. As a simple example, I have a canned 1 second strobe feeding a counter. I can use the counter as a contact to close when it reaches zero. Does all of the" business" have to happen on the right? For example, the left side of the IF/(contact) statement can I put something like a bit comparison on the left? Something like... Counter, Bit# Or do I have to use a bit comparison on the right and its binary result as a contact and put it on the left?     Thanks    
  3. If you decide to use a CJ2M with an added MD21* for your motion application then this article in the downloads sections is very useful. Though written for a CJ1M it is still applicable to the CJ2M.

  4. I/O fatal error

    Thank you very much Sleepy. I had the same issue.
  5. Relay Digital signals

    I have a CJ1M-CPU13. It will be used for a prototype and later if successful, a better PLC fit will be employed. This system does not have the ability to drive pulses for servo control. However, will this system relay a digital signal at ~1kHz? I also need the PLC to count the pulses, reset at 1000 and start again continuously and never miss an input pulse. I see that the published transactions give  <15 microsecond decision times. I would think it would be no issue. Thank you.
  6. Puls train.

    Mine is a CJ1M-CPU13. I now see the problem. Thanks.        
  7. Puls train.

    I am using a cj1m with an OD203 output and other input and relay output cards.  I want to use this card to feed pulses to a servo motor.  I see from rise and fall times, the upper output limit of the OD203 is ~1 kHz or greater. That should be sufficient. Here is my example.  I adjust my servo to 1000 pulses per rev.  Using the OD203, I want to ramp up to 1 kHz on a signal. The servo is happily spinning at 1 Hz. On a signal change, I want to stop the servo at the next multiple of 1000 pulses within the ACC rate.  The motor may spin 10 revs and stop or 10000 pulses. Will the card I have work for this application? Can I do this independently with two channels? Thank you.
  8. Getting to memory.

    It makes even more sense now. I have always been in run mode.(There were other modes...) I also wiped the D memory after saving it and everything works as planned. Thank you very much. You guys make this a great and informative site.
  9. Getting to memory.

    It makes a lot of sense now. Using the Monitor function, I now have an idea of what the other banks of memory do. The current PLC I am using was removed from a decommissioned high end piece of automation equipment. It was funny to note that the programmer used the same handful of commands as me. (timers, KEEPs, counters and MOVs. ). After I wiped the many pages of ladder logic, there are values left in the D memory.  So if I understand it correctly, all of the D memory is used by the programmer and with a new program, I am free to use all of the locations of the D memory?  
  10. Getting to memory.

    I see that one can to use MOV to put a constant into W memory. If I write directly on the W memory and save it, the transfer to PLC stays gray and I cannot get it active (black).  
  11. Getting to memory.

    I know enough Ladder logic to get in trouble. Although, I do have a few PLCs controlling machines that I wired and programmed and they are running well (as long as I can remember what those buttons I added do.) I cannot figure out how to get memory into the PLC.  For example, I have a Counter where I have entered the following: CNT 0005 W1 ( I am driving it with a 1s clock and the reset is an external button.)) I then went to working memory and entered a number as position 1 (I entered 234) When I load the program and press the button to reset, CNT is starting at 0. When I move the W memory from PLC to PC there is 0 at that position. All of the boxes are checked when I compile/transfer. Is my CNT format correct? How does one get the memory to the PLC?    
  12. Expand my PCL Horizons

    Thank you very much Garry.
  13. Expand my PCL Horizons

    Hi, I have a couple of C200HS's set up with DIOs and they work very well for me. I use the ladders, Timers, KEEP, and Counters to control hydraulic injection molding machines. Those are the only PLC commands I really know and use.  For a new piece of equipment with solenoids and two speed motors, I will also use DIO cards and I am upgrading to a CJ1M. I do not use PLCs daily but I learn enough to program the machine and whenever, I need to go back to the PLC language, it is a new but quicker learning curve. My issue is this, I have a motor driven/air cylinder locking indexer (lazy susan) with 8 positions. Each station has a magnet for pick-up and one station has 2 magnets for a z-index. When I use a CTR to note the position, I want to store that number in non-volatile memory so when I re-power the machine, I do not have to spin the indexer to the home position.  How do I go about doing this?
  14. Fatal Error?

    Thank you very much innoaloe. You are a PLC saver. I now have an LED/relay switching at 1 Hz. (The Hello World for PLCs, I guess) What a start! I will be driving solenoids soon.
  15. Wipe memory from PLC

    How does one remove the memory from a cj1m or a cqmi? I do not want to see any of the previous programmers code. I only want to start over.