For anyone who may not have access to VCDS I found the fuel trim variables for ME7 logger
here, courtesy of Jibberjive.
Long Term Fuel Trim Partial (note, the fra's are in a scalar form (so you need to subtract 1 and multiply by 100 if you want a percent, for example an fra_w value of 1.02050 is 2.050%)):
fra2_w ;{AdaptationPartialBank2} ; {multiplikative Gemischkorrektur der Gemischadaption (Word) Bank 2}
fra_w ;{AdaptationPartial} ; {multiplikative Gemischkorrektur der Gemischadaption (Word)}
Long Term Fuel Trim Idle ('per time', which just means that these variables aren't necessarily the real final 'idle fuel trim' percentage that the ECU is multiplying the final fueling by, rather these just give you an idea of which side the idle fuel trims are on (+ means that the ECU is adding fuel because it's too lean, - means the ECU is pulling fuel because it's too rich), so these just you just show you which direction to adjust the fueling, not necessarily the magnitude to adjust it. The real variables for the final value of the idle LTFT's (rka_w/rka2_w) aren't defined automatically in the .ecu file created by the ME7Logger program. Also note that these values are in percentages, so a value of 1.0500 is 1.0500%):
rkat2_w ;{AdaptationIdleBank2} ; {additive Gemischkorrektur (pro Zeit) der Gemischadaption Bank 2 (Word)}
rkat_w ;{AdaptationIdle} ; {additive Gemischkorrektur (pro Zeit) der Gemischdaption (Word)}
Short Term Fuel Trims:
frm2_w ;{LambdaControlAvgBank2} ; {schneller Mittelwert des Lambdaregelfaktors (Word) Bank 2}
frm_w ;{LambdaControlAvg} ; {schneller Mittelwert des Lambdaregelfaktors (Word)}
Hopefully this'll help someone else out