PHD Guiding issues

[xa-coupe]

I've decided to photograph Carina, and after fighting with PHD I've decided to ditch it for the moment.


I've always had issues with alignment that I am finally working though. I've got it good enough now that I'm trying guiding, using PHD.


I can get it running, I can get equipment attached select a star and so on, but as I set it off it's fine for a seemingly random amount of time (went 30 mins once, usually around a few seconds), the RA goes for a wander and goes off the graph sending the total RMS error way over 1. The Dec can either stick about of else it sometimes goes off with the RA though it's generally where you'd like it to be. I turn PHD off and the mount does it's thing.



I tried a new usb cable as that's a common cause of errors but no good. I'm getting there, at least I am making progress.



Equipment

ASI mono camera - laptop - usb to handset- NEQ6.


I'm guessing there's a comm problem as PHD is sending pulses and nothings happening. Anyone got any ideas?

[Startrek]

A few checklist items -
1/ Have you confirmed that PHD2 is actually connected to your mount ( Check in Device Manager ) Also confirm you have downloaded all the latest software both Ascom and PHD2
2/ Are all your settings correctly entered in each section of the Brain ( in particular, the correct guide camera details )
3/ Are you Calibrated ?
4/ Have you set up a Bad pixel map or Dark Library ?
5/ Have you set your guide camera exposure for say 2 sec
6/Is you guide scope focused
7/ I assume your pulse guiding ( direct from laptop to camera) Which is the preferred method , not ST4 guiding (guide camera to mount )
8/ Preferred cabling is from Laptop direct to camera with a USB2 or USB3 cable ( no hubs )
9/ I’m assuming your not using a ZWOASI120MM USB2 guide camera ?? If so , sell it and buy a later model ZWOASI120MM-S USB3 Guide Camera.USB2 Camera has an inherent problem and intermittently disconnects

There are many more items to check but start with the above first and see how you go

Cheers
Martin

Hope others can offer some good advice as well

[xa-coupe]

Thanks for a comprehensive reply!



1. - yes. It does work for a while. It also connects fine at startup.
2. - guide camera is pretty standard, ZWO ASI 120MM-S.
3. - Calibration ... err.. maybe I missed that.. I'll have to look into that.
4. - Yes.
5. - yep.. tried 1 sec, 2 sec and 5 sec .. all to no avail.
6. - yes.
7. - No. From what I have read and seen, the current 'go' is directly to the PC via the handset.
8. - No hubs for that.
9.- definitely a USB 3.


I'm wondering if the calibration is the key. I believed it calibrated when the software started up ... I must have missed the details. Certainly worth a try.


I also suspect the mount. I seem to have some 'weirdness' with it. Sometimes it seems to think the targets are 20 degrees off where they are, after a 2 star alignment followed by a polar alignment. Even a poor alignment shouldn't throw that sort of error.


thanks again.

[kens]

Please attach the guide log.

[The_bluester]

The first time you start guiding it will calibrate, if you have the reload calibration box ticked it will retain that first calibration until you do it again. So if you change anything at all related to the guider (Angle of the guide cam ETC) you need to recalibrate it or it may behave unpredictably.

Are you using EQMOD to control the mount via the USB on the handset (I don't have direct experience of that, my mount is older and has no USB on the handset, I use an EQDIRECT cable plugged in to the mount in place of the handset and run EQMOD that way)

[xa-coupe]

Here's the relevant log file, I don't see anything of interest but perhaps someone with more experirnce will see something;


PHD2 version 2.6.9 [Windows], Log version 2.5. Log enabled at 2020-08-02 19:18:22

Guiding Begins at 2020-08-02 19:50:52
Equipment Profile = NEQ6-SXN90x900_zwo
Dither = both axes, Dither scale = 1.000, Image noise reduction = none, Guide-frame time lapse = 0, Server enabled
Pixel scale = 4.07 arc-sec/px, Binning = 1, Focal length = 190 mm
Search region = 15 px, Star mass tolerance = 50.0%
Camera = ZWO ASI120MM-S, gain = 48, full size = 1280 x 960, have dark, dark dur = 1000, no defect map, pixel size = 3.8 um
Exposure = 1000 ms
Mount = SkyWatcher driver,EQ6 Series (ASCOM), connected, guiding enabled, xAngle = 0.0, xRate = 502.039, yAngle = 90.0, yRate = 1000.000, parity = ?/?
Norm rates RA = 1000.0"/s @ dec 0, Dec = 1000.0"/s; ortho.err. = unknown
X guide algorithm = Hysteresis, Hysteresis = 0.100, Aggression = 0.700, Minimum move = 0.190
Y guide algorithm = Resist Switch, Minimum move = 0.190 Aggression = 100% FastSwitch = enabled
Backlash comp = disabled, pulse = 20 ms
Max RA duration = 2500, Max DEC duration = 2500, DEC guide mode = Auto
RA Guide Speed = 7.5 a-s/s, Dec Guide Speed = 7.5 a-s/s, Cal Dec = 0.0, Last Cal Issue = None, Timestamp = Unknown
RA = 10.75 hr, Dec = -59.9 deg, Hour angle = 3.33 hr, Pier side = East, Rotator pos = N/A, Alt = 51.8 deg, Az = 218.5 deg
Lock position = 23.534, 16.354, Star position = 23.534, 16.354, HFD = 5.39 px
Frame,Time,mount,dx,dy,RARawDistanc e,DECRawDistance,RAGuideDistance,DE CGuideDistance,RADuration,RADirecti on,DECDuration,DECDirection,XStep,Y Step,StarMass,SNR,ErrorCode
1,1.600,"Mount",0.288,0.089,0.288,0.089,0.181,0.00 0,0,,0,,,,3334,38.36,0
2,3.093,"Mount",0.441,0.106,0.441,0.106,0.291,0.00 0,1,W,0,,,,3490,40.14,0
3,4.495,"Mount",0.618,0.332,0.618,0.332,0.410,0.00 0,1,W,0,,,,3438,39.26,0
4,5.919,"Mount",0.713,0.372,0.713,0.372,0.478,0.00 0,1,W,0,,,,3421,39.93,0
5,7.353,"Mount",0.905,0.291,0.905,0.291,0.603,0.29 1,1,W,0,,,,3338,38.75,0
6,8.758,"Mount",1.164,0.374,1.164,0.374,0.776,0.37 4,2,W,0,,,,3394,39.23,0
7,10.309,"Mount",1.058,0.553,1.058,0.553,0.721,0.55 3,1,W,1,S,,,3222,37.47,0
8,11.779,"Mount",1.151,0.708,1.151,0.708,0.775,0.70 8,2,W,1,S,,,3467,40.25,0
9,13.242,"Mount",1.372,0.668,1.372,0.668,0.919,0.66 8,2,W,1,S,,,3572,40.69,0
10,14.709,"Mount",1.442,0.711,1.442,0.711,0.973,0.71 1,2,W,1,S,,,3341,38.97,0
11,16.192,"Mount",1.751,0.984,1.751,0.984,1.171,0.98 4,2,W,1,S,,,3405,39.64,0
12,17.659,"Mount",2.020,1.009,2.020,1.009,1.354,1.00 9,3,W,1,S,,,3377,39.26,0
13,19.123,"Mount",2.087,1.032,2.087,1.032,1.409,1.03 2,3,W,1,S,,,3216,38.44,0
14,20.591,"Mount",2.455,1.361,2.455,1.361,1.645,1.36 1,3,W,1,S,,,3310,38.94,0
15,22.142,"Mount",2.481,1.394,2.481,1.394,1.678,1.39 4,3,W,1,S,,,3408,39.00,0
16,23.615,"Mount",2.507,1.426,2.507,1.426,1.697,1.42 6,3,W,1,S,,,3513,40.53,0
17,25.131,"Mount",2.587,1.441,2.587,1.441,1.749,1.44 1,3,W,1,S,,,3210,38.01,0
18,26.615,"Mount",2.708,1.440,2.708,1.440,1.829,1.44 0,4,W,1,S,,,3370,38.69,0
19,28.078,"Mount",2.904,1.672,2.904,1.672,1.958,1.67 2,4,W,2,S,,,3118,37.09,0
20,29.545,"Mount",3.241,1.818,3.241,1.818,2.179,1.81 8,4,W,2,S,,,3216,38.11,0
21,31.023,"Mount",2.971,1.806,2.971,1.806,2.024,1.80 6,4,W,2,S,,,3106,37.07,0
22,32.548,"Mount",3.213,1.869,3.213,1.869,2.166,1.86 9,4,W,2,S,,,3241,38.26,0
23,34.011,"Mount",3.485,2.005,3.485,2.005,2.347,2.00 5,5,W,2,S,,,3182,37.65,0
24,35.478,"Mount",3.512,2.063,3.512,2.063,2.377,2.06 3,5,W,2,S,,,3380,39.79,0
25,36.942,"Mount",3.701,2.384,3.701,2.384,2.498,2.38 4,5,W,2,S,,,3514,40.71,0
26,38.413,"Mount",3.768,2.454,3.768,2.454,2.549,2.45 4,5,W,2,S,,,3281,38.10,0
27,39.884,"Mount",3.739,2.486,3.739,2.486,2.534,2.48 6,5,W,2,S,,,3282,38.08,0
28,41.356,"Mount",3.735,2.513,3.735,2.513,2.530,2.51 3,5,W,3,S,,,3277,38.09,0
Guiding Ends at 2020-08-02 19:51:34

Log Summary: calcnt:0 gcnt:1 gdur:43 gacnt:0
Log closed at 2020-08-02 19:51:35

[Sunfish]

In my case the problems were mechanical .
1. Cone error and making sure the optical axis matches the mount axis
2. Tighten up loose fittings such as the puck . Give the whole thing a rattle and see.
3. Make sure there is no play in the worm drive, particularly dec
4. Setting the right numbers , focal length , for a large number of steps in the calibration
and a large correction allowed for guiding. Makes the numbers high enough to work.
5. Balance the scope on the mount perfectly.

I do not think the orthorganality warning is much of a guide and anything below 12 degrees is good.

After that things were great with less than 0.6 error all night but if things are going to go wrong they will go wrong with high invisible cloud, poor focus of the guide scope or OAG , loose guide camera cabling and in the West.

[Startrek]

One question I forgot to ask , are you using a software based Goto and tracking program like EQMOD or just using the handcontroller to navigate ?
If your mount is a Skywatcher eq5 , HEQ5, EQ6 or EQ6-R I’d recommend you take advantage of eqmod which is a free open source Goto and tracking program. It also allows you to use PHD2 pulse guiding ie: laptop direct to guide camera. The developers of PHD2 recommend this way of guiding
“Calibration” amongst other things is probably the most important part of setting up your guiding. The bottom tool bar indicates your status including calibration ( a green symbol Cal is indicated )
I recommend you read the PHD2 manual to grasp the fundamentals of guiding

Here’s some more tips on PHD2 guiding from my library -

PHD2 Set Up and Guiding tips

1/ Try to Polar align to around 1arc minute error on Alt and Az

2/ “Auto select guide star” (recommended by PHD2) or manually select star that’s not too bright or saturated to avoid lost stars

3/ If guiding is poor ( above 2 arc seconds ) utilise the Guiding Assistant

4/ Check and adjust focus of your guide scope and camera to minimise lost stars

5/ Set your guide camera exposure time between 2 and 4 seconds ( Looping ) 2 seconds is a good starting point

6/ The SNR value of the guide star should be between 15.0 and 40.0 to avoid losing the guide star

7/ Don’t over correct settings , under correcting will let you manage your guiding performance better

8/ If Guiding is poor try and keep your min mo above 0.25 in RA and DEC . Don’t go above 0.6. A good starting point for min mo is 0.20 or 0.25

9/ Important- Build a Dark Frame library and a Bad pixel map to provide good calibration and stable guide star. PHD2 will only allow you to use one or the other

10/ The RA Osc value should be between 0.3 to 0.5
If it drops to 0.1 or lower then increase the RA aggressiveness or decrease the hysteresis
If it gets quite high say 0.8 then reduce the RA aggressiveness or increase the hysteresis

11/ Use Ascom Guiding - Laptop direct connect to mount ( preferred by PHD2 Developers) in lieu of ST4 connected guiding via camera to mount

12/ USB 2 cable to camera is not to exceed 5 metres

13/ Try and avoid cabling through a hub even a Powered hub, direct connect to the computer , you will have less issues

14/ Ensure you have the latest driver installed for your guide camera

15/ If guide camera is USB2 make sure you connect into a USB2 port with USB2 cable
If the guide camera is USB3 it most probably will connect with a USB2 cable

16/ Ensure you enter all the correct data for your guide camera into PHD2 brain tabs

17/ Make sure you get good Calibration. Calibrate within 10deg of celestial equator and within an hour of meridian
Once Calibrated save it and reuse it ( go to Brain in guiding tab and tick box “Auto restore Calibration”)

18/ if you lose guide star often , go to Brain in guiding tab and increase “Search region” and increase “ Star mass detection”

[kens]

Your guide log shows your setup parameters are way off.
I would use the EQMOD driver rather than the Skywatcher driver. You will need to install that first. In EQMOD set the guide rate to 0.5 as the default is way too small
In PHD2, create a new profile from scratch. Choose as the mount EQMOD ASCOM HEQ5/6
Create your darks library
Choose a star near Declination 0 and well above the horizon and calibrate.
Run the guiding assistant for 10 minutes or so and accept its recommendations

[Sunfish]

+1 EQMOD. No hand control.

[xa-coupe]

Thanks guys, I am trying to find some time to work on the suggestions. I'll look into EQMOD as a priority.

[Startrek]

Jeff
If you want I can send you A to Z procedures for EQMOD using Stellarium as your planetarium ( navigation - Goto and tracking ) plus eqmod settings for PHD2
Is your NEQ6 Mount new or an Older model ?
Does you NEQ6 Mount have a USB port as well as the handcontroller Com port next to each other , or just the handcontroller port and autoguide port side by side ??

Martin

[xa-coupe]

That would be awesome thanks Martin.


Mine, despite being purchased new recently, is an older model with the serial port. I've been considering buying an adapter (rs232-USB) but haven't got around to it. I did pick up a WiFi adapter for it at some stage if that makes it better?

[Startrek]

Jeff
I’m old school , no wifi just good ol reliable cable connections from mount to laptop ( if that’s ok )
Martin

[xa-coupe]

My preference too. Still not sure this WiFi thing will catch on ........

[The_bluester]

Word of warning, they are not an RS232 port. They are TTL, so you need the EQDIRECT cable not just an RS232 one.

[Startrek]

Thanks Paul for pointing that out for Jeff
Jeff has pm’d me so I’m sending him all the details and procedures to set up EQMOD on his NEQ6
Cheers
Martin

[xa-coupe]

Thank you .. I'll soon be the proud owner of a useless cable ... but I can at least order the correct one too !

[phomer]

Jeff,


I am not an expert at reading the log file, but it does not look like the mount is responding to the requests.
Are you using a 190mm camera lens?
What happens when you calibrate?
When connecting to the mount what option are you using?


Paul

[FrancoRodriguez]

Sorry if this is a completely obvious thing but do you clear calibration data each set up session? If not, do this, then move the scope somewhere near the celestial equator and press on a medium sized star. The crosshairs will go yellow and move around for a few minutes before guiding

[xa-coupe]

Thanks to those that have given advice. A fair bit's happened since I posted this, some problems have disappeared and others appeared.


I discovered my Synscan handset is totally pooched and eventually failed. I did buy a replacement handset as the warranty dept of Saxon isn't deemed essential. The new handset worked fine but I was convinced to go EQMOD. This is a lot more fun and thanks to some handy people on this forum ( thanks Martin) I had it up and running fairly quickly. I've been working on drift aligning but that has not worked out as easy as I hoped. Between learning this and f%##g clouds I'm getting nowhere. Once the weather clears up I can spend some time working on it again.


I only recently learned to force calibration but it has made no difference.

[Startrek]

Jeff
Please give the Synscan polar alignment routine a go with the handcontroller
I set my EQ6-R mount and 6” newt tonight and polar aligned in 10 minutes with the handcontroller ( see attached PA error which only required 2 iterations)
Then I go back to home position, shut down the mount , disconnect the handcontroller pack it away , connect the EQ Direct cable from laptop to mount , set up eqmod and start my Goto
I tried drift aligning and takes too much time plus your slewing in vastly different parts of the sky at least 40 to 60 degrees apart. With the Syncan method I’m only using 2 stars 10 to 20 degrees apart in azimuth, very quick
Cheers
Martin

[xa-coupe]

Given no matter what I did last night I couldn't get the error below 2800! I've been watching many Youtube videos on the subject and thought I had a grip on the basics... but to no avail. I suspect once I crack it that I'll be wondering why it was so hard.

[I.C.D]

Hi Jeff make sure that everything is tight on your gear ,do you have any backlash problems ,if so fix that and it may fix all the other problems .Once that was fixed most of my PHD problem disappeared

[xa-coupe]

I'm ready to give it all another go.. but someone must have purchased something really nice... those clouds won't go away.