I'm looking for a copy of the vintage firmware from about 2007-2008 for a Serial Communication to MasterBus/CAN bus interface box. It is a .hex file and I believe you can save a copy from your interface box to a computer using the same Mastervolt Masteradjust software that is used to update the interface box from a computer. See Picture of the interface box.
The long story is that I called Mastervolt support about a charger parameter on my Mass Combi 12/4000/200. They answered the question, but then recommended that I update the interface box that connects between the Mass Combi serial bus and the MasterBus with the current firmware. As soon as the update finished, the Mass Combi, which was on shore power and float charging my batteries, stopped charging the batteries and began inverting.
After much experimentation, the inverter's charger would work as long as I unplugged the serial interface from the Mass Combi and powered if off and then on again by the main inverter-off-charge only on the invert front panel. The moment that the serial interface cable is plugged back in, the problem reappears and the inverter has to be power cycled to get it to work again.
I speculate that perhaps there's a pin on the serial interface that is now being driven that wasn't driven with the old firmware and that this is putting the charger into the invert mode. However, I did not try to break out the serial interface to look at the voltages on the pins. It's also possible that the box sends characters to the inverter when it's first plugged in. The company tried to fix the problem first, by sending me a different new masterbus serial interface box in this picture.
The new interface right out of the box had the same problem. Second, I asked the company for the old firmware, which I hadn't saved before doing the update. :( They sent a .hex file but it was newer but the earliest version that they had. It unfortunately has a load error. Perhaps there's a checksum problem with the .hex file. The latest update file from Mastervolt that broke everything was named Serial_Combi Interface_V1.25.hex 239 KB. The file that they sent with an error was named SerialInterface-2011-0120-REV0112-K.hex. They said that was all that they had available and that I should replace my working inverter/charger with a newer unit with a MasterBus / Can interface.
The inverter charger works fine with the serial interface unplugged, and the parameters can be updated with it plugged in. So, it is functional, but if anyone has a valid working copy of the vintage serial interface firmware from 2007-2008 time frame on their computer as a backup or if it can be downloaded from your working serial interface using the Masteradjust software, I would appreciate a copy. If I can successfully load the vintage copy again, it should allow the Master Display to see the inverter again. Now, I just look at the readings from the shunts to see what the inverter is doing. I'd also like to hear if anyone has any additional insights into solving this issue.
So, anyone have any SerialCombi_Interface*.hex file backups or a 2007-2008 box like in the first picture above?
I will pay media and postage fees if needed.