powermeter

powermeter is a program for working with Data Stream digital transducers by CR Magnetics, Inc.. It works with transducers connected to an RS485 to RS232 converter and allows to configure transducers and read all sorts of power and energy data from them.

The program has been developed for Linux, but shouldn't be too difficult to port to other systems.

Supported Transducers

At the moment, the following digital transducers are supported:

• CRD5110-300-25
• CRD5170-300-5

Adding support for other transducers should be pretty straightforward.

Usage

After compiling the program, it offers different operations:

• powermeter --identify A Identify the transducer at address A (0-255).
• powermeter --read A Read current values from the transducer at address A.
• powermeter --clear A Clear the energy totalizer of transducer A.
• powermeter --scan Scan all 256 addresses for transducers. This operation is very slow.

The following two operations are not meant to be used on a bus to which multiple transducers are connected. They are for the initial configuration of your transducers (one at a time!). Using them on multiple transducers will require you to reprogram all your transducers! Use with care, you have been warned!

• powermeter --reset Reset transducers to factory defaults.
• powermeter --set-address A Reset transducers to factory defaults and configure the transducer at address 0 to address A.

Problems

In the case of errors on the RS485 bus (e.g. due to bad wiring), transducers can be messed up and return non-deterministic values. A power cycle of the whole system (transducers + RS232 to RS485 converter) helped in such cases.

Todo

• Add support for other transducer types.
• Add support for scaling values when an external transformer is used.

Author

powermeter has been developed by Oliver Hitz. The author is not affiliated with CR Magnetics.

License

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.