a long time ago i 've used openapc to read my electrical meters via Modbus-RTU. Caused by missing functions in the Modbus-Masters i' ve decided to wait until anyone else asks for.
In the past few weeks there were some questions about modbus.
So i decided to go on with openapc
Today i've installed an instance in a VM (Win7)
I've tested both Masters (RTU & TCP).
I am wondering why it is still not possible to read more than one Word in a single request.
One of the most benefit is to read a lot of words in one request and process them in the software.
So if i need to read two words (4 bytes) each variable i can read the maximum of 4 variables on a device and the Master is full.
Is there a chance to enhance the master to support up to 32 devices?
The parameters should be (each device):
1) Slave-Address
2) Offset
3) Number of Words to fetch
After that we can discuss about functional blocks to process the incoming values an seperate them to pipe them to an LCD-Display in Control-Room.