Program Track Problems With Broadway Limited Paragon Locomotives

Quite a few people have reported problems programming BLI locomotives with both CV reads and writes on program tracks. So here is a procedure you can use to try programming your P3 engines if you experience this issue.

This CV is not in the BLI Paragon3 technical manuals either. The following is from BLI Tech Support. 

BLI tech:

When we designed our latest decoder, we wanted to have a lot of capacitance to prevent pickup issues over frogs and such.

However, that design posed a problem with reading CV's sometimes and in some programming modes because when the energy was used to A) Charge the capacitors, and B) "chirp the motor" - the packet of data could not make it round trip back to the throttle.

Our engineer created CV217 to lessen the amount of power that was given to "chirp the motor" to overcome that obstacle. That's why it's not an NMRA standard - it's a BLI thing.

The higher you set CV217, the less power is given to the motor while programming.

Different throttle manufacturers pulse the program track differently - so we cannot have a "one size fits all" setting by default."  

The following is a recommendation from Ron Bokleman of the JMRI Users Group:

I would start by setting CV217=110 on the mainline using ops mode programming (should not fail), then move the loco to the program track and attempt to read/write CVs in Direct Mode and/or Paged Mode (if one doesn't work, try the other).

If the results are not good, set CV217=90 on the mainline, then move the loco to the program track and attempt to read/write CVs in Direct Mode and/or Paged Mode (if one doesn't work, try the other).

Then, if necessary try CV217=50, then CV217=20, then CV217=10 until you find the settings that are best for your particular set up.

<Author's note>
You can also try increasing the value above 110, if necessary, until you find something that works. Lowering the value will cause more motion in the engines as you are increasing power to the motor.

In the newer versions of JMRI this value is settable on the settings sheet, rightmost column, 4^th from the bottom. See fig 1.

Fig 2 PWM Duty Cycle

This procedure can also be applied to Paragon 4 locomotives but there appears to be less problems with them.

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