QSI sound chip Q1a and CV 24

[john d]

Anyone know what CV 24 is for ?

At higher numbers 170+  it causes the loco to slow faster , but i think you can get the same results with a lesser value  50 or less on CV 4

John

 

 

[JoeinPA]

John:

CV 24, as you have found, is a deceleration adjustment. It appears to function the same way as CV 4. Why both? I haven't a clue maybe someone like Randy can enlighten us.

Joe

[maxman]

CV24 is discussed on page 57 of the QSI manual: http://www.qsisolutions.com/pdf/QuantumDCCRefManual_5_1_0.pdf.

It appears to have a range of minus 127 to plus 127, depending on how one of the bits in the CV is set.  Without really understanding it all, and I could be incorrect, it appears that setting the CV at some number above 127 will not give a valid result.

The description indicates that it "allows the operator to simulate different train lengths/loads".  It also says that it adds to the value of CV4.  I would infer frrom this that there is some way to activate this CV while operating, as it does not seem to be a useful function if it has to be reprogrammed every time it needs to be changed.

[john d]

Thanks for the quick reply.

I've set cv24 at 165 and 200.

200 gives a faster deceleration than 165.

I can get the same result with cv4 set at 25 or 70 and cv24 at zero

If its a duplicate, whats the reason for it?

You can't set negitive numbers with the throttles so what gives?

[rrinker]

CV23 and CV24 are there to provide offsets fromt he basic aceleration and deceleration values in CV3 and CV4. You set CV3 and CV4 to the momentum you want for your 'average' traina nd then adjust CV23 and CV24 to give more or less based on train length. The manual talks about it working in consists - say to get two locos runnign together, they end up with different values in CV3 and 4. You can use CV32 and 34 in the consist to apply an equal offset to both locos even though they start with differing base values in CV3 and 4.

 You get negative values by using numbers over 127 - 0-127 is a positive 0-127, 128-255 is -1 to -127. Notice in the manual page, bit 7 is the sign. So anything 127 and less (bit 7 wouldbe 0) is a positive number, anything 128 or higher (bit 7 is 1) would be negative. i think. They don;t explain it very well and that's counter to most 'computer math' but it is what it is.

       --Randy