Dec encoder connection


Jim Fakatselis
 

I own an AP1100GTOAE and just recently I’ve been getting repeated errors on startup that APCC fails to connect to the Dec encoder. If I tap on the small black Dec encoder housing with the small led, it then frequently gets resolved.  The light changes color to match the RA encoder. I can hear some clicking  

I’ve messaged AP about this issue a week ago and was asked to check the Dec encoder connector to make sure it was seated correctly. I removed it and cleaned both ends with DeOxit cleaner but I still get the errors at startup.  Haven’t had it fail after it’s running after resolving though, only after a power up.  

Any help would be appreciated.  

jim


Mike Hanson
 

Hi Jim,

You description of the LED color indicates the DEC encoder read head ("housing") might be slightly out of alignment.  The read head is attached to the mount with a pair of 3/32" hex screws.  With the mount powered up and parked, loosen these screws and try to make tiny adjustments in the position of the read head while watching the LED color.  The mount should consistently power up with the correct LED color:
Blue or Green = Good
Yellow, Orange, Red = Bad
Blinking, Off - Horrible

Regards,
Mike Hanson


Jim Fakatselis
 

Thank you for your response Mike.

I repositioned the sensor just slightly while loosening with a 1/16 hex wrench. The Dec encoder light is a steady blue color just like on the RA axis.

I have cycled power several times and so far so good.

Will let you now should it recur.

Thank you so much again !
Jim

On Tuesday, June 28, 2022, 10:36:59 AM EDT, Mike Hanson <mikeh@...> wrote:


Hi Jim,

You description of the LED color indicates the DEC encoder read head ("housing") might be slightly out of alignment.  The read head is attached to the mount with a pair of 3/32" hex screws.  With the mount powered up and parked, loosen these screws and try to make tiny adjustments in the position of the read head while watching the LED color.  The mount should consistently power up with the correct LED color:
Blue or Green = Good
Yellow, Orange, Red = Bad
Blinking, Off - Horrible

Regards,
Mike Hanson


Roland Christen
 

It's not a connector issue. It's a spacing issue of the encoder readhead. The readhead has to be spaced very accurately so that it reads the engravings on the encoder ring (which sits under the readhead). The clicking you hear is the Dec motor responding to the encoder correction loop coming on when the readhead puts out the proper signal.

In order for the readhead to produce the proper encoder signal, the light has to be green or blue. If it is yellow, that's marginal, and if it is red, then there will be no signal to the CP4.

You can adjust the spacing of the readhead by loosening the two screws that hold it on, then sliding it back and forth until you get a blue color on the LED. If you cannot get it this way, try placing a thin shim of .002 thou thickness under one end and tightening the screws (piece of Scotch tape or paper will do). Once you get the light to stay green or blue, run the axis around and make sure it works in all Dec positions.

Rolando

-----Original Message-----
From: Jim Fakatselis <pashasdad@...>
To: main@ap-gto.groups.io
Sent: Tue, Jun 28, 2022 5:06 am
Subject: [ap-gto] Dec encoder connection

I own an AP1100GTOAE and just recently I’ve been getting repeated errors on startup that APCC fails to connect to the Dec encoder. If I tap on the small black Dec encoder housing with the small led, it then frequently gets resolved.  The light changes color to match the RA encoder. I can hear some clicking  
I’ve messaged AP about this issue a week ago and was asked to check the Dec encoder connector to make sure it was seated correctly. I removed it and cleaned both ends with DeOxit cleaner but I still get the errors at startup.  Haven’t had it fail after it’s running after resolving though, only after a power up.  
Any help would be appreciated.  
jim


--
Roland Christen
Astro-Physics


Jim Fakatselis
 

Thank you Roland. Mike Hanson responded similarly and I repositioned it to get the blue light on constantly. Hopefully that resolves it. 
I really never saw a red or yellow light come on prior to repositioning it. Tapping it made it change alternately green and blue then completely off I recall.

All is OK for now.

Thank you again.
Jim

On Tuesday, June 28, 2022 at 12:24:06 PM EDT, Roland Christen via groups.io <chris1011@...> wrote:


It's not a connector issue. It's a spacing issue of the encoder readhead. The readhead has to be spaced very accurately so that it reads the engravings on the encoder ring (which sits under the readhead). The clicking you hear is the Dec motor responding to the encoder correction loop coming on when the readhead puts out the proper signal.

In order for the readhead to produce the proper encoder signal, the light has to be green or blue. If it is yellow, that's marginal, and if it is red, then there will be no signal to the CP4.

You can adjust the spacing of the readhead by loosening the two screws that hold it on, then sliding it back and forth until you get a blue color on the LED. If you cannot get it this way, try placing a thin shim of .002 thou thickness under one end and tightening the screws (piece of Scotch tape or paper will do). Once you get the light to stay green or blue, run the axis around and make sure it works in all Dec positions.

Rolando

-----Original Message-----
From: Jim Fakatselis <pashasdad@...>
To: main@ap-gto.groups.io
Sent: Tue, Jun 28, 2022 5:06 am
Subject: [ap-gto] Dec encoder connection

I own an AP1100GTOAE and just recently I’ve been getting repeated errors on startup that APCC fails to connect to the Dec encoder. If I tap on the small black Dec encoder housing with the small led, it then frequently gets resolved.  The light changes color to match the RA encoder. I can hear some clicking  
I’ve messaged AP about this issue a week ago and was asked to check the Dec encoder connector to make sure it was seated correctly. I removed it and cleaned both ends with DeOxit cleaner but I still get the errors at startup.  Haven’t had it fail after it’s running after resolving though, only after a power up.  
Any help would be appreciated.  
jim


--
Roland Christen
Astro-Physics