Modbus profie Satec PM130 Plus

[Desislav]

Hi
I read data from Satec power meter PM130 and map Modbus register to knx addresses. I have a problem with reading and mapping int32 registers.
For example:
Power factor L2
Range: -1000-1000
Units:×0.001
Type:INT32
R/W: R 
Can someone help me with example how to read this type of registers and map to knx address.

Desislav

[admin]

Are you using scripts or creating a modbus profile?

[Desislav]

Are you using scripts or creating a modbus profile?

I create Modbus profile.

[admin]

Try this, since the resulting value has to be multiplied by 0.001, bus_datatype field has to be set to float32, but datatype field (which tells what kind of data is read from ModBus) should be set to int32.

Code:

{
   "manufacturer": "satec",
   "description": "PM",
   "mapping": [
      {
         "name": "PF_L1",
         "bus_datatype": "float32",
         "datatype": "int32",
         "type": "register",
         "value_multiplier": 0.001,
         "address": 13342
      }
   ]
}

[Desislav]

Try this, since the resulting value has to be multiplied by 0.001, bus_datatype field has to be set to float32, but datatype field (which tells what kind of data is read from ModBus) should be set to int32.

Code:

{
   "manufacturer": "satec",
   "description": "PM",
   "mapping": [
      {
         "name": "PF_L1",
         "bus_datatype": "float32",
         "datatype": "int32",
         "type": "register",
         "value_multiplier": 0.001,
         "address": 13342
      }
   ]
}

Thanks for fast reply. I think now the received value is not real ( screenshot in attachment). Value for power factor must be from -1000 to 1000 when is not multiplied.

[admin]

It might have different register/byte order. Try reading registers 13342 and 13343 as uint16 and post what values you get here.

[Desislav]

It might have different register/byte order. Try reading registers 13342 and 13343 as uint16 and post what values you get here.

I think the problem is not reading Modbus register 13342 as int32. May be the value going wrong when transfer it to 4 byte knx variable.

[admin]

You can set bus_datatype to int32 and remove value_multiplier field. This way you can get the raw value that is being read.

[Desislav]

You can set bus_datatype to int32 and remove value_multiplier field. This way you can get the raw value that is being read.

I try but again the value is not true. I made other test with script. I create a script that read value from slave and map this value to Modbus register (LM work as Modbus tcp gateway) , then read the value with Modbus poll. Now the read value is ok (-974). But I need to map the register not to Modbus but to knx.

[admin]

Here you are reading a single register, not a pair and then converting it to int32.

[Desislav]

Here you are reading a single register, not a pair and then converting it to int32.

Yes in the attached screenshot I read a single register. But also I try to read two uint16 registers and store them in int32 knx address again I read wrong value. Can you post the example , may be make a mistake somewhere .