Hi, Sorry to bother all of you this way, I see no other way at this point. I am trying to get a Siemens Masteguard working and found, by trial and error. Has anyone seen this before? I have the following info: 9600 BAUD 8 bits no parity 1 stop The commands look a lot like the SENA protocol except for the messaging format. It reacts as follows Sending ascii command: "UID{CR}" Response: "ID=Masterguard;A700-T;11.00;6AR1700191{CR}" Sending ascii command: "BAT{CR}" Response: "BAT=2;0450.0;100;27.4;24;313.0,313.1{CR}" Sending ascii command: "OUT{CR} Response: "OUT=2;49.9;217.0;00.0;0000;000{CR}" Sending ascii command: "ALM{CCR}" Response: "ALM=01;0;0;0;0;0;0;0;0;0;1;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0{CR}" Sending ascii command: "TST{CR}" Response: "TST=0;0;0;0;0;0;0{CR}" On the internet it seems that more people are looking for information. This version is from before the time that Siemens sold the design to Choride. The funny thing is that the CPU control board for old and new versions is the same. Only the firmware is different. The hardware design is similar for all devices. Switch mode step down power supply to charge the batteries Switch mode symmetrical step up to + and - 375 volt using FET bridge Half bridge using IGBT to chop the +- 375V to a true sinus Optional additional power supply to battery voltage (half the power rating of the unit). So that the output is frequency unrelated to the input. The difference between smaller and bigger units is in the coils, transformers and number and or size of FET's and IGBT's The units use 24V (2*12) 37V (3*12) or 96V (8*12) battery depending on power and available up time WARNING THERE IS NO GALVANIC ISOLATION!!!!! The advantage is a smaller, lighter and more power effective unit. Regards, Robert -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.alioth.debian.org/pipermail/nut-upsuser/attachments/20140220/36d54d96/attachment.html>