KY WONG

MrPLC Member
 View profile  See their activity

  • Content count

    17

  • Joined

  • Last visited

Posts posted by KY WONG

  1. Posted

    Hi, I am learning on Schneider PLC  Programming. May I know is the Schneider PLC Programming have a same function of "Block move"  in Mitsubishi PLC which can move a few number of address value to another address in once time. What is the code of it?Example,  I wish to move %MW1 (Int) until %MW10 (Int) to %MW100 (Int) until %MW110 (Int). Is there any code can done it in once? I am using Schneider PLC TM241 model with Somachine V4.3 Programming Software. 

    @Wasan, Hi, Do you familiar with Schneider PLC Programming? 

     

     

  2. Posted

    Hi friends,  

    I am using G(P).CPRTCL to create the RS485 communication code to control my OMRON Temperature controller Modbus. However, I find out that the generate crc-16 code for my comment is different from the calculated MODBUS CRC-16 . How can it be? I am using predefine function of PLC. It should give me a correct crc-16 right?  @Wasan, @kaare_t

  5. Posted · Edited by KY WONG

    Hi friends,  

    I am facing a problem. When my device is suddenly disconnect with RS485 modbus connection, my QJ71C24N card is not no error coming out and it refuse to continuous sending out signal even my program is keep calling on for G(P).CPRTCL . How can I reset the situation without turn off my PLC and how can I detect it which is not given me any error condition?  @Wasan @kaare_t

  10. Posted

    Any one  have any experience to due with Parity Error when RS485 input can't get? Below is the circuit trace i get. It shown me that Parity Error when input signal from my device. But some of the time I can get the input message completely. Sometime can't. Is there any way to solve it?  

    Capture6.JPG

  14. Posted

    23 hours ago, Wasan said:

    @kaare_t Thanks for clarify this I have confused about Modbus CRC from predefined protocol for non precedure protocol it cannot automatic create CRC you need to create manually.'

    But for ASCII comunication just terminated string with <CR><LF> (H0A0D) it will collect data to buffer by G.INPUT function.

    @Wasan My device end code is <CR> only. It mean that my receive complete code specification setting is 13(Dh) right? The entire received input will go to specify buffer memory right?  

     

  15. Posted

    23 hours ago, kaare_t said:

    Regarding this point it is not defined which CRC you need. I'm pretty sure that the built-in CRC are ment for the MELSEC protocol and not when using "NonProcedural Protocol". In other words you need to write the CRC yourself. I might have some examples written in GX IEC Developer or GX Works2 (don't remember). Also, the topic starter is using ASCII and not binary, are you sure you are looking for a CRC (and not a sumcheck)?

    @KY WONG: Which CRC do you need? Do you have a spec?

    @kaare_t I wish to understand about the checksum. For your information, my ASCII Modbus device is using CheckSum8 Xor. Is there any PLC code can generate the Checksum for it? For your information, now I temporary off the function of checksum in my device function. 

    Before this, I have used the FX PLC RS485 communication (RTU modbus format). As  I know there is a PLC code to generate the CRC-16/Modbus. Is the Q series having the special code to generate the CRC too? 

  16. Posted · Edited by KY WONG

    Mr. Wasan, May I know is the signal reply timing will affect the result too? Because I saw there is some adjustment of the time of feedback signal. Is the timing of feedback will affect the feedback signal in my PLC? & Is there any command in Q series plc to calculate the CRC value for RS485? 

  17. Posted

    I am using QJ71C24N to communicate with my devices, ASCII mode. I can send my output to the device by using non-protocol method ( G.output). However,  when I using G.input to try to receive the feedback from my device. The signal seen not stable to receive by my PLC. Sometime can get the full signal sometime can't and sometime I get some messy signal. Is there any setting I need to set to get the stable feedback from my device? Please anyone can help me to solve this problem?