QJ71C24N Sum Check Calculation Buffer Memory Location?

2 posts in this topic

Hello all,

I'm using MC Protocol Format 4 to communicate with a VB6 application on a PC.

I want to make some slight modifications, and I am getting a sum check error being returned by the module to my application.

I believe (haha) I am calculating the sum check code correctly for Format 4 as most commands do work (reading for example).

I was wondering if anyone knew of the buffer memory location on the QJ71C24N card that stores what the card is calculating for the sum check?

This way I can have a troubleshooting tool to see what I am calculating wrong.

I have looked through the manuals (application/basic) for the C24 already as well as the Melsec Reference Protocol manual. 

I have attached the error code for reference, again, I am only looking for what the C24 calculates as the sum check code.




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I'm pretty sure that the CRC is not stored in an accessible buffer memory for the built-in protocols. Can't you monitor your own VB code, just create som temporary int's to see what you're sending? Or just sniff the serial line?

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