PM (performance monitoring):
RenCnt: DCM renormalization count – a high number may indicate problems in DCM (extremely rare)
RenBlw:DCM renormalization blow-up count – how many times DCM had to completely rebuild the DCM matrix since the last PM. Normally innocuous but a number that constantly grows may be an indication that DCM is having troubles calculating the attitude (extremely rare)
FixCnt: the number of GPS fixes received since the last PM message was received (it’s hard to imagine how this would be useful)
NLon: number of long running main loops (i.e. loops that take more than 5% longer than the 10ms they should)
NLoop: the total number of loops since the last PM message was displayed. Normally 1000 and allows you to calculate the percentage of slow running loops which should never be higher than 15%.
MaxT: the maximum time that any loop took since the last PM message. This should be close to 10,000 but will be up to 6,000,000 during the interval where the motors are armed
PMT: a number that increments each time a heart beat is received from the ground station
I2CErr: the number of I2C errors since the last PM message. Any I2C errors may indicate a problem on the I2C bus which may in turn slow down the main loop and cause performance problems.