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, UPSTemperature,AmbientTemperature,Humidity,LineVoltage
Any value that is not supported by your UPS such as AmbientTemperature and Humidity will be blank; the commas before and after that field will still be output.
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