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Posted: Sun May 04, 2008 3:36 pm
by maglito
I can connect now...thanks!

What would cause the AF in Nistune to disagree with what my plx says? WOT seems to be ok, but closed loop seems to be way off. My AF shows to be 19-20 on Nistune, but 14-15 on my plx display. Any ideas?

Posted: Sun May 04, 2008 7:57 pm
by Matt
The PLX outputs a number from 0 .. 255 which we convert into a number 0 - 5000 millivolts (0-5 volts)

This is then uses a lookup table in the
C:\Program Files\NIStune\Wideband\PLXDevices\AFR1.csv file

The contents of those map the millivolts to AFRs
AFR
0000,8
5000,32

Looking at section 3.2 of the PLX Users guide you can map the AFRs of the PLX with 0 -5 volts to AFRs

You must use the same lookup tables to get the same reading in this AFR1.CSV file within NIStune for your wideband sensor

The R-300 unit has tied to

Byte Mapping:
Decimal 0 = 0.68 lambda = 10AFR (gasoline)
Decimal 255 = 1.36 lambda = 20 AFR (gasoline)

Yours might be like the above (I've now changed future installs to have the R-300 mapping above) or perhaps configured differently

Posted: Mon May 05, 2008 1:44 am
by maglito
My PLX R-500 has the same mapping as the R-300.

I changed the values in my lookup table to

0, 10
5000, 20

Everything works great!

Thanks for all the help

Posted: Mon May 05, 2008 12:34 pm
by Matt
No problems. Good to see its all working well