I looked in forums and the only thing I could find was the discussion on M-bus which is the European standard for reading water/gas meters. The US standard is the Sensus ICE Register which is an ascii based command/response protocol. You can get the standard from Sensus by signing non-disclosure docs for something they call open source…but I was wondering whether anyone actually has written some script for this so I don’t have to re-invent the wheel. Since this is an ascii protocol I assume that means it is either based on rs232 or rs485, but I have no evidence of either at this point. I also get the impression there is a pulse that is issued be the master to get the meter to send the response.
Anyone actually know anything about this protocol?
Apparently we have some customers who use devices from Piigab which translate from Modbus to M-Bus. Might that be an option?
M-Bus is not just a ASCII protocol based on RS232/485. It uses 2-wire cable and the meters can be powered via that cable. The data transfer is done via modulating the voltage level over the wire. A “1” is 36V and “0” is 24V.
To connect a M-Bus meter to a standard RS232 port, you need to use a level converter device. This device needs to be specified based on the number and kind of clients/meters in the M-Bus network, to provide enough power.
Here in Europe we have several applications that connect either Opto-EMU or SNAP-PAC systems to M-Bus. We use external Modbus to M-Bus converters and connect them to the RS232 or RS485 port of the Opto 22 controller, or just via Ethernet using Modbus-TCP. The devices are from Piigab, as Mary has mentioned already.
M-Bus 900.
I am not aware of anyone that has implemented the M-Bus protocol in PAC Control and just uses a external M-Bus level converter.
I hope this helps,
Gerhard
Well I did mention M-bus but I already had the impression that Mbus was the European standard initiated by Germans for Germans…as one guy put it. Also, I found that ABB also makes a module as you describe.
I was referring to the standard developed in the US by Sensus meter and it is as I describe it above, however I don’t know much more than that. I have long used Krohne mag meters but apparently Sensus has decided to third party label the new Krohne 3000 series and they are selling it through their exclusive dealership at $4,330 fr a 4" and $6274 for a 6" mag. In the past I thought Krohne was expensive but based on this pricing not so much. Anyway many of the new meters are all coming out with the AMR connection so that these new all encompassing software companies like Itron can read the meter data (on a simplistic basis). They typically don’t read rate they just extrapolate it. Now the engineers are specifying the job with the intent that the control system doesn’t even collect the data…
Btw Mr. Gerhard,
On a different note, I am having a specific driver built using Profibus and using the Opto22 Profibus card to talk to Kollmorgen’s S700/S300 series drives. IN case you are not familiar with Kollmorgen, it is an America based company that Danaher bought that makes a whole line of very sophisticated servo drives and motors and is part of the same company (and in the same building) as Thompson drive components. These S700/S300 lines are made in Germany.
