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Split from Cannot open port on CB-1241.

I had the same problem - check a connection ( A and B replaced?)

see the pic - it works fine, TIA v13 sp1

Hello,

for first guys check really LED statuses how they work. Problem can be with swapped wires, other problem can be wrong register address value. If you don't be sure you can also connect some PC application to PLC as Slave sim instead of real device for check. Then you can see where you do problem.

Kaulquappe

This is the connection you need. The slave will only respond when it recognized a correct frame. And then Rx is blinking.

I guess you did not evaluate the outputs of MB_MASTER correctly. Please note: the outputs are displayed dynamically. That means, they are only available one cycle.

Regards,
Kaulquappe 

 Hello,

What do you mean by "outputs are dynamically displayed".

I created DB to store that data, i used that DB at DATA_PTR for storage of data.

I observed there was no TRUE at DONE terminal of MB_MASTER.

There always a TRUE at BUSY terminal of MB_MASTER as long as REQ is TRUE.

Regards,
PCNS

Duris_I

Hello,

for first guys check really LED statuses how they work. Problem can be with swapped wires, other problem can be wrong register address value. If you don't be sure you can also connect some PC application to PLC as Slave sim instead of real device for check. Then you can see where you do problem.

 Hello,

As you suggested i have used the Slave Sim to test my program.

please find the attachments.

I have been getting Response Exception code 02.

I have changed Reg size, Data type, Read only, Read/Write, Offset all the combinations, still i'm getting exception code.

Connections are also correct, i'm sure about it.

Even i tried changing the modbus address from "41350" to "401350" in both PLC program and Slave Sim, still exception error is coming.


Regards,
PCNS

Hello,

but this looks like what I mentioned as one of possible problem - wrong register address value. Check that again, look to first Picture with response frame, there is also this info. Also what Kaulquappe sugested to you, simply pay attention to output statuses, you can't simply look to them via Online status, you must prepare conditions to check them because you can simply miss their values.

Update: check simply that Slave sim register DATA address, you have set offset 40001 but your request address is 1350, this is wrong.

Duris_I

Hello,

but this looks like what I mentioned as one of possible problem - wrong register address value. Check that again, look to first Picture with response frame, there is also this info. Also what Kaulquappe sugested to you, simply pay attention to output statuses, you can't simply look to them via Online status, you must prepare conditions to check them because you can simply miss their values.

Update: check simply that Slave sim register DATA address, you have set offset 40001 but your request address is 1350, this is wrong.

 Hello,

Thanks for the suggestions.

Seems like what you said is correct, but i don't know , i'm getting results with my settings which are visible in the pic.

At last i'm able to get the data.

I have been looking for TRUE at DONE of MB_MASTER, it is not showed, but i'm getting data at the pointer.

Now i'm able to read and write data now.

thank you very for helping me.

With Regards,

PCNS