MBus and Siemens UH50 meter

[tomnord]

I have 3 UH50 heatmeters that is battery operated. They only update data each 15min. What is the correct way to set up LM as GW for these devices?
I use a MBus to RS232 gateway.

[admin]

Use a scheduled script. Check this guide: https://kb.logicmachine.net/integration/mbus/

[tomnord]

That's probably right, but when the meter only sends each 15mn, it is in sleep mode the remaining time. It's turning into quite a challange to sync LM and meter.

[admin]

M-Bus provides both data and power over two-wire connection. This means that the M-Bus module is permanently powered even though the meter itself uses battery power. You can probably read the data at any time but it won't be real-time measurements.

[tomnord]

None of the meters are responding to adress scans eighter.. It was based on that I thought that values only was available every 15min.

[admin]

Have you configured short address on each meter? M-Bus module might use a different baud rate like 1200 or 4800.

[tomnord]

yes, i think so.. strange.. I also have the secondary adresses of the meters, but how does the mbus.scansecondary function work?

i only get this error;

Code:

attempt to call field 'scansecondary' (a nil value)
stack traceback:

[admin]

You have outdated firmware.

[tomnord]

Code:

SW: 20230607

[admin]

Install 2024 RC1.

[BrentW]

Code:

SW: 20230607

Hi Tomnord, 

Any update on how you went with this integration? 
We are also integrating with the UH50 using Mbus and the meters do have some peculiar behaviours.

Brent

[tomnord]

Code:

SW: 20230607

Hi Tomnord, 

Any update on how you went with this integration? 
We are also integrating with the UH50 using Mbus and the meters do have some peculiar behaviours.

Brent

I got it to work, had some issues with cables. All values ar updatet each 15min, but previous value is stored in mBus buffer. 
Script below with separated GA's.

Code:

-- config init
if not meters then
  require('mbus')

  -- time to wait between each meter read
  sleeptime = 10
  -- use /dev/RS232 serial port with 2400 baud rate
  mbus.init('/dev/RS232', 2400)

  -- meter definition
  -- addr - short address
  -- id - number from data table where value resides
  -- div - optional divisor for convertion to the final value
  meters = {
    { ga = '3/0/0', addr = 10, id = 4, div = 10}, --  kW, dpt 14.
    { ga = '3/0/1', addr = 10, id = 2}, --  kWh dpt 12.
    { ga = '3/0/2', addr = 10, id = 5, div = 1000 }, --  m3h dpt 14
    { ga = '3/0/3', addr = 10, id = 6 }, --T1    dpt 12.
    { ga = '3/0/4', addr = 10, id = 7 }, -- T2   dpt 12.
    { ga = '3/1/0', addr = 20, id = 4, div = 10 }, --  kW
    { ga = '3/1/1', addr = 20, id = 2}, --  kWh
    { ga = '3/1/2', addr = 20, id = 5, div = 1000 }, --m3h
    { ga = '3/1/3', addr = 20, id = 6 }, --T1   
    { ga = '3/1/4', addr = 20, id = 7 }, --T2  
    { ga = '3/2/0', addr = 30, id = 4, div = 10 }, --kW
    { ga = '3/2/1', addr = 30, id = 2}, --kWh
    { ga = '3/2/2', addr = 30, id = 5, div = 1000 }, --m3h
    { ga = '3/2/3', addr = 30, id = 6 }, --T1   
    { ga = '3/2/4', addr = 30, id = 7 }, --T2    
  }

  -- reset meter values on first run
  for _, meter in ipairs(meters) do
    meter.value = 0
  end
end

-- read each meter
for _, meter in ipairs(meters) do
  res = mbus.getdata(meter.addr)

  -- read ok
  if type(res) == 'table' then
    data = res.data[ meter.id ]
    value = nil

    -- get current value
    if type(data) == 'table' then
      value = tonumber(data.value)
    end

    -- value is valid and different from previous read
    if value and meter.value ~= value then
      -- apply divisor if set
      div = meter.div
      dpt = div and dt.float32 or dt.uint32
      if div then
        value = value / div
      end

      -- update group address value
      grp.update(meter.ga, value, dpt)
      meter.value = value
      --log(meter.ga, meter.value, dpt)
    end
  end

  -- wait for next read
  os.sleep(sleeptime)
end