M-bus problem

[Andrea Becagli]

Hi, 
I am having problems reading data from m-bus meter. I have Caleffi Conteca Easy with M-Bus (750705) a Techbase M-Bus to rs485 Converter (MBus10) and a LM, i am trying with this script:

Code:

require('mbus')

mbus.init('/dev/ttyUSB0', 9600 ,"half")


res, err = mbus.scan(1 , 10, 1)
log(res)
log(err)
log(mbus.getdata(7))

 to scan for the Caleffi meter (address:7) and to read some data from it. As a result i get this:

Code:

m-bus 17.05.2023 12:07:52
* table:
[1]
  * bool: false
[2]
  * bool: false
[3]
  * bool: false
[4]
  * bool: false
[5]
  * bool: false
[6]
  * bool: false
[7]
  * bool: false
[8]
  * bool: false
[9]
  * bool: false
[10]
  * bool: false
m-bus 17.05.2023 12:07:52
* nil
m-bus 17.05.2023 12:07:54
* arg: 1
  * nil
* arg: 2
  * string: failed to send/receive frame

I have tried changing polarity of the m-bus and of the rs485 connection with no result though. Could you help me?