Modbus RTU using RS232

Hello.

Conglich

I work with Video:

https://www.youtube.com/watch?v=xbjPuWesEkk&t=6s

I did parameter for Com Load. :((
I simulator and it work

What Jay is suggesting is that you use a PC with special software for temporary. This temporary connection can help to see if the PLC side is working as expected. Diagnostic tools in the PC software can be very helpful.

Knowing that the PLC is working will make it easier to then connect the real master device.

You said: "I simulator and it work"
What does this mean? What simulation was done? (My internet is weak so I cannot watch the video.)

Consider to place your test program on the forum as a ZIP archive. It is more easy to go through all the small details.

Ensure the cable is correct. The TX and RX lines makes a cross over:

TX(master) -> RX(slave)  
        .... master transmit to receiving slave

RX(master) <- TX(slave)
        .... master receiving from to transmitting slave

 
BR

 Hi 
This is my project. 
you can download and fix it for me :( 

#dP

Hello.

Conglich

I work with Video:

https://www.youtube.com/watch?v=xbjPuWesEkk&t=6s

I did parameter for Com Load. :((
I simulator and it work

What Jay is suggesting is that you use a PC with special software for temporary. This temporary connection can help to see if the PLC side is working as expected. Diagnostic tools in the PC software can be very helpful.

Knowing that the PLC is working will make it easier to then connect the real master device.

You said: "I simulator and it work"
What does this mean? What simulation was done? (My internet is weak so I cannot watch the video.)

Consider to place your test program on the forum as a ZIP archive. It is more easy to go through all the small details.

Ensure the cable is correct. The TX and RX lines makes a cross over:

TX(master) -> RX(slave)  
        .... master transmit to receiving slave

RX(master) <- TX(slave)
        .... master receiving from to transmitting slave

 
BR

Conglich

 Hi 
This is my project. 
you can download and fix it for me :( 

I do not fix other people's code for them without their payment clearing the bank first. And then my company name needs to be added on the author list. I avoid doing internet-only business.

I do not like the fact that your buffer (DB1) contains mixed data types. Best would be to use only WORDs.

Consider looking at the in-software help for the title "Sample program for a Modbus slave". Start with that first. But you can reduce the buffer from 100 to something smaller.

Add code to capture "MB_COMM_LOAD_DB".STATUS when "MB_COMM_LOAD_DB".ERROR = TRUE. Same for "MB_SLAVE_DB".STATUS when "MB_SLAVE_DB".ERROR = TRUE.

 thanks for a lot
But I think I find out solution for my project. 
Tomorow, I am going to test it. thank you so so much

#dP

 

Conglich

 Hi 
This is my project. 
you can download and fix it for me :( 

I do not fix other people's code for them without their payment clearing the bank first. And then my company name needs to be added on the author list. I avoid doing internet-only business.

I do not like the fact that your buffer (DB1) contains mixed data types. Best would be to use only WORDs.

Consider looking at the in-software help for the title "Sample program for a Modbus slave". Start with that first. But you can reduce the buffer from 100 to something smaller.

Add code to capture "MB_COMM_LOAD_DB".STATUS when "MB_COMM_LOAD_DB".ERROR = TRUE. Same for "MB_SLAVE_DB".STATUS when "MB_SLAVE_DB".ERROR = TRUE.