Modbus Newbie Question, where to start?

XBee & XBee Gateway XBee - Zigbee
1

I have a limited understanding of what the X2D ZB gateway is capable of with Modbus.

Questions: Can I use the ESP tool to create a dia that configures Modbus mapping through the gateway (X2D)?

If so, are there any existing Modbus objects (in the ESP tool) that can be modified?

Aside from turning Modbus “on” in the Industrial applications menu by creating a Modbus TCP table, I am assuming I need to script (in Python) the sensor data map to the Modbus table. Is this correct?

There are lots of good Modbus resources that describe the mechanics of Modbus in detail, I am struggling with how to get the zigbee sensor data (I am using a Digi L/H/T sensor) onto a Modbus stream through the gateway to my Modbus Master (control system).

Any pointers, suggestions, or comments are welcome.

Regards,
Greg

2

Unfortunately Digi hasn’t gotten the Modbus and ESP integrated yet.

There is a lot of (too much?) info on the Modbus section of the Wiki:
http://www.digi.com/wiki/developer/index.php/Category:Modbus
http://www.digi.com/wiki/developer/index.php/Modbus_Dia_Server

But I think for now it could be largely a do-it-yourself issue to understand how the pieces go together.

But I can easily say that the L/H/T sensor has no clue what Modbus is. The above code would use the ‘iDigi Dia’ framework to collect the sensor data, then a custom modbus derived device would understand how to convert the Dia channels into Modbus responses.

1 Like
3

Thanks Lynnl,
Yes, there is a lot of information.