I am trying to interface a MODBUS IP device with Mango. I encountered this problem: my device needs a request of minimum 10 register for a valid response (e.g.: from 30001 to 30021 where each register is composed of 2 words) . There is some way to do this? Thanks for your suggestions.
One is not sufficent ...
This should be fairly easy. You will want to have data points created to fill in the range from 30001 to 30021. This would be a data point for each offset set as a 2 byte signed integer or one for every other register set as a 4 byte.
Next make sure your Max read register count is more than 20. It should default to 125. If you have issues you could try it with and without the Contiguous Batches Only check box.
If you have issues you can also use the Log IO option to log the raw modbus traffic and see the exact Modbus request that Mango is sending.
Let us know if that works.
Thanks for your prompt response. This is the screenshoot of my data source creation:
![alt text](image url)
As you can see in the MODBUS read data window, I am able to read twelve registers of my device but when I try to test the point locator I receive the message "Unknown exeption code: 0". I followed your instruction to reduce the value of "Max read register count" but the result is the same. I also attach the screenshoot of the "Point details".
Where am I wrong?
The point locator tool will not work as by it's nature it only request one register. You will need to create all the data points and then enable your data source and view them on a watch list.
Great! Thanks for your instructions! Now I can read all the registers without problems. Mango is the right software for us.