Welcome to our Learning CentreUse our online documentation as a reference book to answer your questions.
MODBUS RTU Gateway’s Parameters
Name (field): enter the title for your KNX gateway;
Protocol (drop down): choose the protocol to match with the gateway;
Enable (check box): it allows to enable /disable the selected gateway;
Address (field): connection address (for X1 and X3 it sets the RS485 port to use)
Port (field): TCP port (for X1 and X3 it’s not needed);
Connection timeout: sets the timeout milliseconds to wait for the connection (only valid when TCP gateway is used)
Read interval: delay between each read on the bus
Receive timeout: raise an error after this milliseconds timeout when a request does not receive a correct answer in time.
Connection CRC error timeout: raise an error after this time when a message is received but with CRC error
Wait for interval if frame failed: delay before sending again messages after an error
Wait for interval if frame success: delay before sending a message
Byte order: define the protocol byte order (MSB = Most Significant Byte before) (LSB = Least Significant Byte before))
ASCII transform: must be checked when the protocol is defined as ASCII format
The RTU protocol needs some more information to set up the serial communication:
Baudrate: 300 – 115.200
Parity: Odd, Even
Stop bits: 1,2
If the device uses the serial communication directly (X1, X3) you can define them with the corresponding drop-down selectors.
If an IP to RS485 is used you have to read the manual of your gateway to setup it, usually from a webpage of the gateway
On Raspberry PI if you attach a USB device as gateway usually the address will become /dev/ttyAMA0
Here is the connector of EVE X1 explained: