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serial rs232 cable help?

Discussion in 'General Electronics Chat' started by BryWY, Apr 6, 2016.

  1. Les Jones

    Les Jones Well-Known Member

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    BryWY,
    In your post #67 you have not got the connections quite right. I am assuming that you have bought a straight through (Pin 1 to pin 1, pin 2 to pin 2 and so on.) 9 pin male to 9 pin female cable and that you have cut the cable. I also assume that you are joining the wires is chock block (Screw connector strip or whatever you call it in your county.) You should have pins 1, 4, & 6 at the PC (Female) end joined to pins 1 & 6 at the plotter (Male) end. So brown, yellow and blue from the PC end should ALL be connected together an be connected to brown and blue from the plotter end. (You need to connect the blue wire from the PC end to this terminal on the terminal on the connector strip. (So there will be 5 wires joined together.) I think that your problem now is that without handshaking the PC is sending data faster than the plotter can handle. I suggest that you connect the blue wire from the PC end and set the flow control back to the way it was and see if that solves the problem. If you post the flow control options that you have to choose from and tell us how it was set when it worked with the original cable we may be able to work out what is wrong rather than just guessing.

    Les.
     
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  2. BryWY

    BryWY Member

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    FLOW CONTROL SET TO HARDWARE i THINK WE ARE GETTING SOMEWHERE....WILL TRY A BIGGER JOB
     
  3. BryWY

    BryWY Member

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    FANTASTIC ...I CANNOT THANK YOU ENOUGH.....
     
  4. dave

    Dave New Member

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  5. BryWY

    BryWY Member

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    OK NOW TO CONVERT PC END TO USB i HAVE A GENERIC 340 CONVERSION SET BUT LAST TIME I TRIED IT CUT THE DECAL BUT WENT WONKEY AT THE END SIMILAR TO WHEN FLOW CONTROL WAS TURNED OFF

    330 AM HERE SO WILL HAVE TO GET SOME SLEEP...BUT THIS IS AWESOME
     
  6. Les Jones

    Les Jones Well-Known Member

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    You are still not making things clear. Is this with connecting the blue wire or without ? Is this with the flow control now set the way it was originally ? Are the flow control options just - None, Hardware, XON / XOFF or do you have the choice of which handshake signal are used for hardware flow control. The more information you can supply when asking for help the more logical deductions we can make. For example I now get the impression (But do not know for a fact.) that you cant solder the wires to the connectors. Giving this information would change the ways suggested to solve the problem. Testing the voltages on the plotter connector when I asked early on in the thread would have saved a lot of time as it would have established if a straight or crossover cable was required.

    Les.
     
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  7. BryWY

    BryWY Member

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    sorry got excited yes after connecting blue wire things are good...flow control set to hardware as per setup instructions in manual i no longer have but remember
     
  8. granddad

    granddad Active Member

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    Agree , Its been 30yr but seem to remember plotters were DCE or was it DTE ( sorry ) think breakout box is way to go
    Edit I see OP has a result congrats all round,
     
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  9. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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    This thread wasn't systematic from day1. Can we blame it on overworked and tired. It seems like Les and I were getting confused.

    I was hoping initially for:
    (Voltages relative to pin 5)
    1
    2
    3
    4
    5
    6
    7
    8
    9

    Similar voltages at the PC end, would have helped too.

    Didn't realize you were breaking the cables in the middle and making connections.

    Anyway, you got it. I just thin we could have gotten to the end point sooner.

    The manual is the first line of defense. The breakout box is the second.
    Measuring voltages is an ersatz breakout box. The reason why it helps is that you can't have voltage on the same pin on both sides.

    Now write this cable information up (M,F) and put it somewhere - including here. Include the baud (9600), flow (Hardware), Data (), Stop bit() info.

    So, yep there's a 9-pin connector of the "wrong" gender on the plotter.
    "Wrong" is relative with RS-232.

    The "good news" is that with RS-232 switching wires haphazardly won't screw things up. At least for the 9-pin version.

    Note here: http://www.arcelect.com/rs232.htm

    under V.24/RS232 Interface nearly all of the signals on the 25 pin connector are used. They were even nice enough to provide test signals.

    My two worst RS-232 issues were:
    1. A Macintosh (RS-422) talking to an RS-232 motion controller. I had to introduce a better driver.

    2. The RS-232 Driver chips kept blowing up on an X-ray diffraction machine. I had to add isolators.

    I did work in the era when Bell (the telephone company) owned the modems.

    18 alerts this morning. A record. It's great that Les and I are on opposite sides of the big pond. We often find that we complement each other. Thanks Les. I was about ready to throw in the towel out of frustration.
     
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  10. Les Jones

    Les Jones Well-Known Member

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    Hi KISS,
    The frustrating thing is when OPs don't answer questions. I requested that a table was made of the voltages with respect to pin 5 for both the PC end and the plotter in in my first post on this topic. (Post #24) Later on I asked if there was any links between pins and if any of the pins had not had wires soldered to them on the broken male end. (I think you eventually managed to get him to give you some of this information. I agree that the OP should fully document the information that you suggested. Also when he gets the correct cable to meter it out in case my guess is not quite correct. If there is any forum related to these plotters he should also post the information on that forum.

    Les.
     
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  11. BryWY

    BryWY Member

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    I want to Thank you guys for hanging in there with me to get this issue resolved ...I apologize for lack of info on my end...I have to blame it on ignorance it's my only defense. In researching this issue there are are a number of people having similar issues with these plotters ...I will do my best to inform them of this solution. You guys were amazingly helpful and patient in helping me get this job done.
     
  12. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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    And amazingly patient. :banghead:
     
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