Re: help with AP900 guiding via ASIAir Pro

Ray Gralak

Hi Steve,

I see the problem. The old firmware that you have (Rev 'E' chip) requires separate start and stop commands to issue guider moves, but the driver is sending timed moves. Timed moves handle starting (and stopping a guider move after the supplied duration value) from within the control box.

However, I think the old firmware in your mount is handling this as a simple start move and the move continues while waiting for a stop command. Since the driver expects the control box to stop the move after the supplied duration, the driver does not send a stop move command. Thus, the GTOCP2 firmware keeps the guider move going until you stopped it with an appropriate key press on the keypad.

I think you should be able to fix this problem by selecting the correct mount type and controller in the AP V2 driver setup. That is, make sure you have AP900 as the mount type and GTOCP2 as the controller. In one of your logs you have GTOCP4 selected as the controller and no mount type. This will cause the driver to potentially send commands that the GTOCP2 will not understand, like the timed moves.

-Ray Gralak
Author of APCC (Astro-Physics Command Center):
Author of PEMPro V3:
Author of Astro-Physics V2 ASCOM Driver:

-----Original Message-----
From: [] On Behalf Of
Sent: Tuesday, June 16, 2020 7:07 AM
Subject: Re: [ap-gto] help with AP900 guiding via ASIAir Pro

Hi Ray,
ASCOM driver logs attached...thanks!

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