Re: Seeking CP3 Control Box with V2 Chip

Christopher Erickson


CPx controllers always know the worm gear positions of both axes by saving them to NV memory just before losing power when power is disconnected. A freshly-connected CPx controller has no idea where the worms are positioned when first connected.

"Always take the high road. There's less traffic."

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii

On Thu, Oct 7, 2021 at 7:59 PM Bill Long <bill@...> wrote:
Wouldn't the new box know that once it's powered on and connected to the motors?

From: <> on behalf of Christopher Erickson <christopher.k.erickson@...>
Sent: Thursday, October 7, 2021 7:44 PM
To: <>
Subject: Re: [ap-gto] Seeking CP3 Control Box with V2 Chip
I don't agree. Changing CPx controllers requires that a new PEM recording takes place. There is no way for a new CPx controller to know where the old CPx controller left the worm gear positions at.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738

On Thu, Oct 7, 2021, 3:50 PM Chris White <chris.white@...> wrote:
For those interested, I spoke with Dave today and as long as the mount doesn't move it is OK to download your PEC curve, change CP's and then upload that curve to the new unit.

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