Hi,
I've finally got around to making up a cable to connect my Inovate MTX-L AFR gauge to my Moates APU-1 so I can start logging with wideband data.

My problem is there seems to be a .5 difference in AFR between what the MTX-L gauge shows on it's digital display and what I see on the TunerPro dashboard e.g. 15:1 is shown on the MTX-L while 15.5:1 is shown on the TunerPro dashboard.

I have an 8625 8192 Baud PCM $0D Mask ID.
I followed EagleMarks ADC Interface channels setup guide to edit my ADX file so that it could display the output from the MTX-L.
I initially set it up with the payload size set to 63 but had no activity on the dashboard so I then tried a value of 65, on cold start TunerPro was only displaying the AFR in the 10:1 range while the MTX-L gauge was showing around the more believable 14:1. I then changed the payload size value to 67 and things started to look like they were working.
I've connected to ground and channel 1 on the APU-1, according to the guide the value 67 corresponds to channel 3?
I'm not sure why I had to change that, does the payload value vary between different bin's?
Any idea why my MTX-L display and my TunerPro dashboard are out by .5 and what the proper way to sort it out?
I've attached the values I've set up in my ADX file incase someone can see an obvious mistake.