MODBUS RTU MASTER FOR CP340/341/441-X (NO DONGLE REQUIRED)

You can simply use the DONE output from the MBMAREQ function block in combination with an on delay timer to detect a communication loss.

The DONE output should be triggered every time the request has been successfully executed (reply from the slave received).

So you just need to program an on delay timer and trigger that timer with the negation of the DONE output.

The timer will elapse and detects the error if the DONE output stops getting triggered due to any reason (wire broken...).

Best Regards.

TIBI68

Hi TIBI68.

First, I'd like to thank you for all your hard work on this. I've sent you a PM asking for your help with my case if you don't mind having a look at that. Thanks in advance.

 Dear TIBI68,

Thank you for the great blocks! I was able to implement it in two of our machines.

TIBI68

I try to avoid working with TIA whenever I can

Are you able to migrate the MBMA340.ZIP project into your TIA?

I was able to integrate it in projects made, both, in Step7 and TIA Portal 13. After migrating and copying your blocks, I only had to select the library version for P_SEND and everything worked like a charm.

Thanks again and have a good day!

Cheers, Wojtek

The Moderator moved your post here while it was absolutely right were it was.

Sorry to hear about your problem and I will try to help you.

I have currently some issues opening your program, STEP7 message about the polish project language, but I am working to solve it.

In the meantime I would try to change the LINK parameter on all the blocks to another, 100% unused address.

The LINK parameter is the interface between the MBMAxxx and the MBMAREQ block and, if you see the value online, should show the instance data block number of the MBMAxxx block.

In case that number changes due to any reason the MBMAREQ block will try to open a wrong or non existing data block and your CPU goes to STOP.

I changed my windows regional settings to polish but cannot open your project.

Best Regards.

Kindly change the LINK parameter on both blocks to an unused address.

I also have screens from stacks when PLC has stoppe, maybe it is also helps.

Best regards

goblin

I've change the LINK address (MW10->MW100) and I'll see if that helps but it take a couple of days.

I also attach corrected project, TIBI68 - can you try to reopen it?

Thanks 

goblin

 Hi Goblin

goblin

I've change the LINK address (MW10->MW100)

 Did you make sure if there is no other data stored in ranges as: 

M100.0 to M101.7

MB100 to MB101

MW99 to MW100

MD97 to MD100

It might seem like overkill to check so many ranges but I had similar problems where it turned out that my MWnn was used by Mnn.x. Better safe than sorry.

Good luck with your project.

Cheers,

Wojtek

Wojtek, I've checked all addresses if there are no conflict witth another (MW10 before I changed when TIBI68 gave me suggestion, and MW100 now).

I don't know what is inside MBMAREQ block, but just in case I've changed LINK address and I will see what's happen. But it takes a couple of weeks to ensure that problem was with wrong LINK address.

goblin

Today it happened again.

Still the same diagnostics errors:

When I went to HW CFG/PLC/Operating Mode and perform "Warm Restart" program has run again.

I attach files from Stack dumps when CP was in STOP mode.

TIBI68 can you take a look at it? I'll be gratefull for your help.

thanks

goblin