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Posts posted by ORSO2001


    flickering Bit

    Dear All,


    I put online the PLC with the PC to check step by step my program and I found that 3 exclusive BIT (coil) are flickering and not enable the contact; to be more clear the function part has to do 3 individual string check and this check is always enabled; I saw that the BIT status switch very fast between 0 and 1; the operands after (store, inverted contact, coil, reset) are ok.

    I use this BIT only in this case; they are not called in other position...when coils are active it has to load a specific screen...I have set this function by Action menu...and It doesn't work!


  2. Dear All,


    I have connected the UNITRONICS by RS485 port (CPU protocol) at 1 slave;I read only 1 register (but is the same if I try with 20 or more) and the buffer that come back has the byte of the address located for last! in the attached pic you can see that the B8 is the "request" and the B45 is the "answer"...B45= first byte from the left is "3" for function, second is "2" for the lenght, third and fourth are "3,231" are the value 999 that is correct, fourth and fifth are "248,254" for the CRC ...and last byte "0"!? 
    how I have to do for have back the correct sequence?
    thanks in advance.


  3. Dear All,


    yesterday I have downloaded the last sample programs from the site and I understand that I really wrong everything...please accept my apologise if I have wasted your time with my uncorrect question...I am less then a beginner and I have learn more...now I know that I have to insert a tag with indicate the array lenght in the slave session and what I have tried before is for the TCP.
    I hope next time my question will be done in a properly way.
  4. Dear All,


     searched in the forum but I don't found what I need...and I can't insert a pic of the "question"..I can upload only 29.9 Kb!
    I tried to use the element "modbus read builder" to read a lot of registers together...
    in the point "A" I insert an "modbus request" with: protocol=0; function n°=3; slave ID=1; start address=0; number of operands=39; ethernet trns.= nothing.
    in the point "B" I insert a BUFFER (that I created in GLOBAL tag) with 8 "array".
    In the point "D" I insert a "modbus request descriptor" with: expected response=43 (I have read it after the first test...and is what I expected...if I have understood the modbus RTU protocol); protocol=0;function=3; start address=20; number of operands=19; ethernet=nothing.
    For the point "C" (request size) I tried different "tag" (buffer, int,uint..) but nothing seems work!
    When I tested the "program" I have had the following response from the buffer in the point "B": 1,3,0,0,0,39,5,208.
    in the tags that I tried to use for the answer (it is an answer?) I have always "0" in each point...
    What I have to do?
    thanks in advance


  5. Dear Sarangani thanks for your quick answer.

    For sure I misunderstand the meaning of "ladder function n°"...after reading your message I checked in the "help" of Unilogic about "ladder function"...If I understand each ladder function can has many regions and each region can has many row...it is correct? In the help I found that exist a instruction called "jump to region"...maybe I have to create a new region instead of a new "ladder function" and, at the end of the first region, insert the jump to region instruction...it is correct? however I don't found or better I don't understand how I have to do for enable or jump from a "ladder function" to others...can you help me in this way?

    Thank in advance

  6. Dear All,


    I am approching at PLC world then excuse me if the following question will be "stupid":

    I create a screen with two numeric boxes (dec); one is for the value one is for the "item" (called 1 and 2) that will have the value; each item has a differente modbus register. I thought that if I use an "equal" function to compare the number of the item and enable an "store" fuction to write the register but it doesn't work...if I simulated it the red line stop in the middle of the two fuctions (equal and store)...what I have wrong or I forgot?...attached some pics about what I have.


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