AEM 03-0310 Analog vs Serial

[tbrtuning]

I am eventually planning on getting my wideband reflashed for CAN logging but wanted to know the best way to be using it right now?

I have been using it with a serial to USB adapter but have read that analog output is better but never saw much reasoning.

[dr.mike]

For the X-series AEM widebands ( 30-0300 and 30-0310 ), the analog output is, generally, preferable to the serial output.

The new AEM widebands have a differential analog output; that is used to compensate for ground offset errors. This makes a huge difference in accuracy.

The Analog- wire of the wideband is not really a ground wire. It is an input wire that the wideband uses to determine what the logger THINKS proper ground voltage actually is. Then it uses that voltage to set the voltage on the Analog+ wire to match the correct differential.


e.g.

The wideband wants to signal a value of 2.5v to the logger ( for whatever lambda value that is )

If the wideband measures 0.3v on the Analog- pin. It adds that value to the 2.5v it normally would have used. And, it outputs 2.8v ( 2.5v + 0.3v ).

But, to the logger, that 2.8v appears as the original proper 2.5v value.

Thusly, the signal is "auto-corrected" for ground offsets between the wideband and logger. ( within the limits of the power rails )


To use this with the MPVI PRO:

Connect the wideband brown wire ( Analog - ) to the GND pin of the MPVI ( pin 5 or 6 ).
Connect the wideband white wire ( Analog + ) to the A/D INPUT x pin of the MPVI ( pin 1 .. 4 ).

This will cause the wideband to use the MPVI ground as its reference voltage. Thus, compensating for errors caused by differences in ground voltage between the MPVI and the wideband.



The analog output of the 30-0300/30-0333/30-0310 runs at 500Hz (2ms) with 10-bit resolution.

The serial output runs at 10hz (100ms) and is only 3-digit data xx.x AFR.

I don't consider the serial data to be super useful.

[tbrtuning]

I really appreciate your taking the time to post such a detailed response. I will switch to using analog like I did with my old UEGO and maybe then I will really see the benefits to the X Series. I did not have much better luck trying to copy and paste tune VE with the X Series than my old UEGO so thought I would look into possibly not getting data the best way.

[dr.mike]

Yes. the serial output is much too slow to give good synchronized/correlated data.

I think the upper limit for this is around 30ms.

[fcar1999ta]

For the X-series AEM widebands ( 30-0300 and 30-0310 ), the analog output is, generally, preferable to the serial output.

The new AEM widebands have a differential analog output; that is used to compensate for ground offset errors. This makes a huge difference in accuracy.

The Analog- wire of the wideband is not really a ground wire. It is an input wire that the wideband uses to determine what the logger THINKS proper ground voltage actually is. Then it uses that voltage to set the voltage on the Analog+ wire to match the correct differential.


e.g.

The wideband wants to signal a value of 2.5v to the logger ( for whatever lambda value that is )

If the wideband measures 0.3v on the Analog- pin. It adds that value to the 2.5v it normally would have used. And, it outputs 2.8v ( 2.5v + 0.3v ).

But, to the logger, that 2.8v appears as the original proper 2.5v value.

Thusly, the signal is "auto-corrected" for ground offsets between the wideband and logger. ( within the limits of the power rails )


To use this with the MPVI PRO:

Connect the wideband brown wire ( Analog - ) to the GND pin of the MPVI ( pin 5 or 6 ).
Connect the wideband white wire ( Analog + ) to the A/D INPUT x pin of the MPVI ( pin 1 .. 4 ).

This will cause the wideband to use the MPVI ground as its reference voltage. Thus, compensating for errors caused by differences in ground voltage between the MPVI and the wideband.



The analog output of the 30-0300/30-0333/30-0310 runs at 500Hz (2ms) with 10-bit resolution.

The serial output runs at 10hz (100ms) and is only 3-digit data xx.x AFR.

I don't consider the serial data to be super useful.

THANK YOU DR MIKE!!!!! I have been to the end of the Internet today trying to figure out which connection is best.