SU1400 RM with Amnesia

[Brad_C]

I recently arrived home from holiday to find the brains of my trusty SU1400 RM scrambled.

Something completely corrupted the eeprom and the unit had no idea who or what it was.

Judicious use of Google led me to be able to re-set the model, serial number, manuf date and other misc details. I managed to calibrate the battery voltage, load power and line voltage ok. I got lost however when re-setting the constants 4,5,6 & 0.

I found a number of different sets of constants on the net so I set about methodically trying different constants while running charge/calibrate cycles to see what is what.

Along the way I discovered some stuff I had not seen documented elsewhere, so I thought I'd post it here in the hope someone might be able to help me out with the constants for my unit.

First some details.
The unit is an SU1400 RM. Firmware 162.4.I KWI. Manufactured 1/24/03 and with a board marked Rev 8. The board is SMD (unlike my trusty SU2200 which is through hole). The board also has a version G3.5 on it (as does the processor).

The Model code I had to set in the firmware is 0x92 which gives 162.4.I KWI.
I've wound up with the following constants thus far :

0 - battery const - 0x83
4 - Unknown - 0x11
5 - Unknown - 0xF1
6 - Unknown - 0x60
P - Power calibration - 0xED
B - Battery voltage calibration - 0xE5
L - Line Voltage - 0xDC

To facilitate rapid recharge cycles I've been taking the batteries out and charging them using different hardware. I found in PROG mode you can re-set the battery state to believe the battery is at 100% using ^F (not seen that documented anywhere).

Also, ')' appears to be a long settable text constant. I've not found a use for it yet, but you can set it yourself and it also comes up as part of the data when you hit ^B.

All the info I've found thus far has constant 6 set upwards of 0xF0. It appears this constant sets the point at which the UPS decides the battery is empty. The lower it is set, the lower the battery voltage before it screams empty.

I've had to set it on or below about 0x60. When it was up at 0xF0 the unit would immediately go into low battery when you disconnected the power. Having it set down around 0x60 allows me to perform what appears to be a pretty accurate (based on previous experience) battery calibration cycle.

Constant 5 appears to have something to do with the instantaneous assessment of battery level when the unit transfers to battery, but I've not been able to really get much of a feel for what 4 or 5 do.

All in all I think I know my UPS a lot better than I did, however I'd really just like it to behave like it did before I went away!

If anyone has an SU1400 RM 162.4 (voltage is not important), I'd really really love to know what your constants 4,5 & 6 are.

I recently rebuilt mu SU2200 when it smoked some MOSFETS and most of the driver circuit, so I'm not completely daft when it comes to electronics, nor firmware.

Now, I've read this forum quite a bit, and I'm not expecting support from anyone, however just perhaps someone might have the data I'm after if I'm really lucky. It'd be interesting to know what ')' is for also. I'd love to talk to Ron Leblanc. He seems to have written the calibration document I found from '95
Interestingly this document refers to Rev 7 & 8 firmware, yet mine was made in 01 and has Rev 4.

Anyway, enough unstructured ramble for a first post.

Cheers.