Iskra MT174 via RS485

Add-ons Bindings
1

Hello,
There is good binding IEC 62056-21 Meter Binding and good meter iskra mt 174
But there is a problem to get data from meter.
MT174 (in addition to IR port) has RS485 port to communicate via IEC 62056-21 protocol. All looks good, I use usb to rs485 converter to get data.
BUT Iskra MT 174 use FIXED badrate at 9600 to communicate via RS485
It NEVER answer at 300 as prescribed according protocol.
I discussed this situanion with developer of IEC 62056-21 Meter Binding - he is very busy to help me.
What we need:
Make a fork of IEC 62056-21 Meter Binding, that initiate connection at 9600 exept of 300.
I hope it is enough to change only couple line of code
Line 218
serialPort.setSerialPortParams(300, SerialPort.DATABITS_7, SerialPort.STOPBITS_1, SerialPort.PARITY_EVEN)
To look
serialPort.setSerialPortParams(9600, SerialPort.DATABITS_7, SerialPort.STOPBITS_1, SerialPort.PARITY_EVEN)
And
Line 55
private static int[] baudRates = new int[]{300,600,1200,2400,4800,9600,19200};
To look
private static int[] baudRates = new int[]{9600,19200};
PLEASE HELP
If any ecslipce developer can do it?

2

Who are interested.
I’he already resolve my problem switching to NodeRed
smartmeter node support custom baudrate for a link
With connecting to influxdb and grafana it looks pretty good.
I can share my results.

3

Dear Vasylkov,

I was asked to read the same meter Iskra MT174, and it has not worked with 300 baudrate as you mentioned. Did you finally get it working with 9600 baudrate?

4

@GreenUkr I am interested i your node red solution since I couldn’d manage to get it started. Could you please share your solution?

5

Hi
I used node-red-contrib-smartmeter + influxdb (to store data) + grafana (for visualisation)
If you give me your email, I can send json file for node red.

6

Thanks a lot! I found out how to solve it by myself. My solution:

  1. I run a second Pi with raspian and node-red (comes pre-installed)
  2. On Nodered (Link: your-raspberry-ip:1880) Install Smartmeter node via menu - manage palette
  3. Parameters which worked for me: /dev/ttyUSB0:300-7E1 (Source Type Serial; Serial Port /dev/ttyUSB0; Baud 300, Bits 7, Parity Even, Stop Bits 1)
  4. Protokoll DO, Transport SerialRequestResponseTransport, Request Interval 0. → Deploy
  5. Connect a Function to the Smartmeter-node to format the output:

return [
{payload: parseFloat(msg.payload[„6-0:1.8.1″].rawValue.replace(/[^\d.-]/,“))},
];

  1. Install Openhab Connect via menu - manage palette
  2. Connect Openhab-Out to the Function and define your openhab-parameters within the node
7

My congratulations

Best regards,
Gennadiy Vasylkov

8

Hello, I AM interesting un how to read 1.8.0 y 2.8.0 from Iskra mt174, can You hello me, thanks.