Playing with the examples for electric vehicle charging requires a setup with a contactor as showin in the image below. The schematic is also available PDF.
Connect pin 2 of J1 to +12V to enable contactor operation.
For just playing with Modbus communication and a signed snapshot, it is sufficient to just power the meter and connect a RS-485 interface.
The tools used in these examples require the runtime for the Python language to be installed on your system. You will need version 3.7 or higher.
On a typical Linux or macOS desktop system, Python 3 should be available out of the box and you should get a version information similar to:
$ python3 --version
Python 3.9.1
Windows does not come with Python 3 installed. So pick the latest release from https://www.python.org/downloads/ and install it. Check Add Python 3.x to PATH in the install wizzard for having Python immediately at hand at the command line interface later.
We are using Python package command line scripts to provide the BSM Tool. On
Windows this directory is automatically added to your search path where on
Linux and macOS you have to manually add it. This directory is typically
$HOME/.local/bin and on macOS $HOME/Library/Python/3.9/bin. You have to
take care for your actual Python version in the latter case.
We provide installation packages on GitHub. These packages can be installed with Python's package installer pip3 which should have been installed along with Python. You should get a version information similar to:
$ pip3 --version
pip 20.3.3 from /usr/local/lib/python3.9/site-packages/pip (python 3.9)
Having Python 3 and its Package Installer ready, you could easily install the BSM-WS36A Python Support as follows:
$ pip3 install https://github.com/chargeITmobility/bsm-python/releases/download/release-0.12.0/bauer_bsm-0.12.0-py3-none-any.whl
Now you should be able to run the BSM tool and display its help output
$ bsmtool --help
usage: bsmtool [-h] --device DEVICE [--baud BAUD] [--timeout SECONDS] [--unit UNIT] [--chunk-size REGISTERS] [--trace]
[--verbose] [--public-key-format {der,raw,sec1-compressed,sec1-uncompressed}]
COMMAND ...
BSM Modbus Tool
positional arguments:
COMMAND sub commands
models list SunSpec model instances
export export register layout
get get individual values
set set values
create-snapshot create snapshot but don't fetch data
get-snapshot create snapshot and fetch data
verify-snapshot verify snapshot signature (but do not create it)
verify-signature verify arbitrary signature for a given public key and digest
ocmf-xml generate OCMF XML from already existing snapshots (stons and stoffs)
dump dump registers
version print version
optional arguments:
-h, --help show this help message and exit
--device DEVICE serial device
--baud BAUD serial baud rate
--timeout SECONDS request timeout
--unit UNIT Modbus RTU unit number
--chunk-size REGISTERS
maximum amount of registers to read at once
--trace trace Modbus communication (reads/writes)
--verbose give verbose output
--public-key-format {der,raw,sec1-compressed,sec1-uncompressed}
output format of ECDSA public key (see RFC 5480 for DER and SEC1 section 2.3.3 for details
about formats)
You may specify communication parameters also by environment variables. Use BSMTOOL_DEVICE, BSMTOOL_BAUD,
BSMTOOL_UNIT, BSMTOOL_TIMEOUT, and BSMTOOL_CHUNK.
and you are ready to go.
The BSM Tool does not allow accessing arbitrary register spans. For example, it
always reads the whole register span of a model instance. Therefore some
examples also use PyModbus's console
application pymodbus.console which you could install with:
$ pip3 install pymodbus prompt_toolkit