For UPS models, NBKPRO, SMART, SHARESMART, and MATRIX, the output is written in a format very similar to what PowerChute writes. That is:
MinLineVoltage, MaxLineVoltage, OutputVoltage, BatteryVoltage, LineFrequency, LoadPercent, UPSTemperature,AmbientTemperature,Humidity,LineVoltage, BatteryCharge,toggle
Any value that is not supported by your UPS such as AmbientTemperature and Humidity will be blank or possibly as 0.0. In any case the commas before and after that field will still be output. The toggle value alternates from 0 to 1 on each line. This was added at user request so that no two adjacent samples are identical.
An actual example from the log file is:
Nov 2 12:43:05 matou apcupsd[23439]: 224.9,227.5,226.2,27.74,50.00,100.0,30.6,,,226.2,50.0,1