With some help I got it to work.
I made a new virtual sensor with sensor type P1 smart meter
I changed the sdm120.sh script to:
#!/bin/bash

# Read out modbus meter
#echo Reading values from Eastron SDM120c Modbus Meter, please wait....
values=`sudo sdm120c -a 1 -b 9600 -e -p -P N -q -z 3 -j 20 ...

Thanks
Ok I did
pi@raspberrypi:~/domoticz/scripts $ sudo chmod +x sdm120.sh

Then
pi@raspberrypi:~/domoticz/scripts $ ./sdm120.sh
{
"status" : "OK",
"title" : "Update Device"
}
{
"status" : "OK",
"title" : "AddLogMessage"
}

What does this mean?
Still can not see it in Domoticz.

I did ...

Unfortunately not. It gives the same error.

My sdm120.sh script.
#!/bin/bash
#title :solar
#description :Read current from sdm120 and sends it to Domoticz.
#author :JM
#date :20160605
#version :0.1
#usage :./solar
#notes :
#bash_version :
#==============================================================================
SERVER="http://192.168.1 ...

Yes I did at first, no difference. I have it every 10 sec so it refreshes in the same speed as my P1 meter. Then I can see the real electricity use.

Hey All,

Very new to Pi but I love it.
I have a Eastron SDM120 modbus with a RS485 usb and connected it to my Pi 3 B+.
I installed https://www.domoticz.com/wiki/Eastron_SDM120C and made a dummy.

If I type
sdm120c -a 1 -b 9600 -P N -S 2 -z 1 -j 20 /dev/ttyUSB1

I get

pi@raspberrypi ...