Skip to content

Latest commit

 

History

History
100 lines (86 loc) · 4.46 KB

Documentation.md

File metadata and controls

100 lines (86 loc) · 4.46 KB

MBUS to UDP converter

System decription

The converter consists of a interface card mounted on a Raspberry Pi Zero. Input is a stream of meter data on a MBUS interface. Output is a stream of JSON objects sent to a UDP port on a extern server running Node Red. Network connection is via RPi's internal wifi card. The converter card is supplied from the MBUS line, Raspbery Pi is sypplied from a separate 5V power supply. RPi and converter card is connected via three pins in the GPIO header - 3,3V, UART RX and GND.

The converter card

A MBUS interface IC NCN5150 needs a small number of external components to function. Connection to the smart meter is via standard ethernet cable (MBUS uses pins 1 and 2) through a RJ45 socket. The converter card has the same header pins as the Raspberry Pi. It is possible to connect all the 40 pins, but it is not required. Only three pins must be connected.

Data stream from smart meter

This description is for Kamstrup smart meter, all the other meters should follow the same standard (see the NVE note).

There are two data blocks. One is sent every 10 seconds, one every hour.

Following data are pushed from the meter:

Nr OBIS code Object Descrtiption Unit Scaler
1 1.1.0.2.129.255 OBIS List version identifier
2 1.1.0.0.5.255 GS1 number Meter -ID (GIAI GS1 -16 digit )
3 1.1.96.1.1.255 Meter type Visible string
4 1.1.1.7.0.255 P14 Active power from the grid W 0
5 1.1.2.7.0.255 P23 Active power to the grid W 0
6 1.1.3.7.0.255 Q12 Reactive power from the grid var 0
7 1.1.4.7.0.255 Q34 Reactive power to the grid var 0
8 1.1.31.7.0.255 IL1 Current phase 1 A -2
9 1.1.51.7.0.255 IL2 Current phase 2 A -2
10 1.1.71.7.0.255 IL3 Current phase 3 A -2
11 1.1.32.7.0.255 UL1 Phase or line voltage 1 V 0
12 1.1.52.7.0.255 UL2 Phase or line voltage 2 V 0
13 1.1.72.7.0.255 UL3 Phase or line voltage 3 V 0
14 0.1.1.0.0.255 RTC Clock and date
15 1.1.1.8.0.255 A14 Cumulative hourly active import energy Wh 1
16 1.1.2.8.0.255 A23 Cumulative hourly active export energy Wh 1
17 1.1.3.8.0.255 R12 Cumulative hourly reactive import energy varh 1
18 1.1.4.8.0.255 R34 Cumulative hourly reactive export energy varh 1

Data 1-13 are pushed every 10 seconds, 1-18 is pushed every hour

Data that are not present (if the meter is only one phase) are omitted. Voltage depends on type of grid connection (3 or 4 wire).

Example (from Kamstrup documentation)

7E A0E2 2B 21 13 239A E6E700
0F 00000000 0C07D0010106162100FF800001
0219
0A0E 4B616D73747275705F5630303031
0906 0101000005FF 0A10 35373036353637303030303030303030
0906 0101600101FF 0A12 303030303030303030303030303030303030
0906 0101010700FF 0600000000   
0906 0101020700FF 0600000000
0906 0101030700FF 0600000000
0906 0101040700FF 0600000000
0906 01011F0700FF 0600000000
0906 0101330700FF 0600000000
0906 0101470700FF 0600000000
0906 0101200700FF 120000
0906 0101340700FF 120000
0906 0101480700FF 120000
0906 0001010000FF 090C 07E1081003100005FF800000
0906 0101010800FF 0600000000
0906 0101020800FF 0600000000
0906 0101030800FF 0600000000
0906 0101040800FF 0600000000
C8867E

The interesting data start on line 7. Every data line starts with 0906, then the OBIS code and a data block.

JSON object

There is one object for every value received from the meter. I have choosen this way rather than sending all the data in one object. This way some data will be sent if there is a transmission error. Also the program may be also used for one-phase meters.

The object is defined as such:

data : (string)
value : (float value)
topic : "AMS"

data is a string, it identificates what kind of data is sent

ID Obis code Explanation
power P14 Power (W) consumed from the grid at the moment
powerto P23 Power (W) delivered to the grid
rpower Q12 Reactive power (var) consumed from the grid
rpowerto Q34 Reactive power (var) delivered to the grid
pcons A14 Cumulative consumed power (Wh)
pdelv A23 Cumulative delivered power (Wh)
rpcons R12 Cumulative consumed reactive power (varh)
rpdelv R34 Cumulative delivered reactive power (varh)
amp1 IL1 Current phase 1 (A)
amp2 IL2 Current phase 2 (A)
amp3 IL3 Current phase 3 (A)
vol1 UL1 Voltage phase/line 1 (V)
vol2 UL2 Voltage phase/line 2 (V)
vol3 UL3 Voltage phase/line 3 (V)

value is a float value

topic is a string value "AMS" that allows node red to sort packets according to which device sent them. Effectively it is possible to use the same port and UDP node to receive data from several different devices.