omron e5cn

Discussion in 'General Electronics Chat' started by onlinejames, Aug 25, 2007.

  1. onlinejames

    Thread Starter New Member

    Aug 25, 2007
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    Hi, im trying to set up a e5cn omron temperature controller and get it to log onto our computer, does anyone know of a website or diagrams how to set this up, the diagrams that came with the units are not noob friendly

    what i need to know is from the e5cn-c2mt-500 i will take 2 wires from terminals 11(B) and 12(A) to the ns-al002 232/485 adaptor
    do i screw 12(A-) to RDB(+) and 11(B+) to RDA(-), then run a normal female to female lead from the serial port to com1 on my pc?
    thanks for any help
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    I think on the RS-485 side you want to go + to + and - to -, but don't quote me on that. Why did the printed material give you the opposite idea? When you say you expect the gizmo to "logon" to your PC what exactly are you thinking of? If the PC is not running some piece of software you'll most likely get a whole lot of nothing.
     
  3. onlinejames

    Thread Starter New Member

    Aug 25, 2007
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    Im running cx thermo software, the paperwork that came with it didnt actually specify anything, thats why im asking
    im looking at logging temps on the pc
     
  4. Papabravo

    Expert

    Feb 24, 2006
    10,136
    1,786
    So you didn't actually see anything in the printed material that suggested hooking + to - and - to +. Is that correct? The worst thing that will happen is that the two ends of the link will have different definitions for "1" and "0". This will prevent any useful communication, but nothing will be damaged electrically.
     
  5. onlinejames

    Thread Starter New Member

    Aug 25, 2007
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    the only thing it says on the omron diagrams is rs-485 A and B
    the communications pin 11 and 12 dont show any polarity in the diagram
    Im not sure where they should go on the 232 to 485 adaptor it has terminals labelled as FG = ground, rdb(+) <- , sdb(+)->, rsb(+)->, nc, rda(-)<-,sda(-)->,rsa(-)->
    any help would be appreciated
    thanks
     
  6. subtech

    Senior Member

    Nov 21, 2006
    123
    4
    It sounds like you've got an isolated (transformer de-coupled) input on the Omron device. If this is the case, the input to the Omron is not polarity sensitive. To make your rs485 side of the converter work (it is capable of either 2 wire half duplex, or 4 wire full duplex comm) you must jumper together the the rdb(+) and the sdb(+). Joining these two terminals together will create a B(+) terminal for your two wire ckt.
    Likewise, do the same with the sda(-) and the rda(-) to create the A(-) terminal for your 2 wire ckt which the omron requires. A straight serial cable from your comm port on the pc to the 232/485 adapter should do the the trick. (not a null modem cable)
    rs485 requires proper cable and termination procedure if it is to be reliable.
    If you are not familiar with rs485, you can educate yourself here:

    http://www.bb-elec.com/RS485.asp

    A google search on your controller came up with this for me:
    http://www.omron.com.au/search_prod/dosearch.asp

    Good luck with your project
     
  7. onlinejames

    Thread Starter New Member

    Aug 25, 2007
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    thanks for that, been a great help, one thing i thought that because i have only one omron controller i dont need to terminate, if i have 2 or more in series then i need to terminate with a 54 Ohm resisitor across the last omron on pins 11 and 12, i may be wrong
     
  8. subtech

    Senior Member

    Nov 21, 2006
    123
    4
    Well, it won't hurt to try without termination, you might get lucky.
    If you add another Omron unit, it should be connected in parallel with the first, not in series. If you anticipate adding other units on this comm line, it would be wise to invest in proper feed line that is designed for use in 485 circuits. Belden, Carol, and others make good cable. Using inadequate cable and improper connecting schemes can lead to some very frustrating problems.
    Good luck on your project.
     
  9. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
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