Synscan ASCOM driver Error

[Healing Bench]

Below is an extract from the attached error log showing when I invoke a slew to target in “Sky Atlas”, NINA reports an error when trying to drive the mount to the intended target.

Version of code::

• NINA version 2.0.0.2054
• Synscan app ascom driver version 130
• Synscan version 11915
• Windows 11 on apple macbook
• EQ6-R Pro with WiFi dongle connected to common Wifi network. Macbook reaches mount via this Wifi network, not via the dongles onboard AP.

To clarify, the Synscan app is launched, NINA interfaces to the Synscan app via the ASCOM driver.

For the most part this software works fine, however, there are periods when invoking a slew just wont work and the ASCOM interface errors.

Changing the target seems the only way to get things working again.

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To be honest, i'm not sure whether this is an issue with NINA and inserting an incorrect correct value to ASCOM or whether ASCOM is not interpreting the incoming values correctly.

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ASCOM.InvalidValueException:  set - '' is an invalid value. The valid range is: . ---> ASCOM.InvalidValueException: unspecified   at ASCOM.SynScanMobile.AscomConversationManager.Converse(Command command, ArgsChecker argsChecker, ConverseParams convParams)   at ASCOM.SynScanMobile.Telescope.SlewToCoordinatesAsync(Double RightAscension, Double Declination)   --- End of inner exception stack trace ---   at ASCOM.DriverAccess.MemberFactory.CheckDotNetExceptions(String memberName, Exception e) in C:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:line 552   at ASCOM.DriverAccess.MemberFactory.CallMember(Int32 memberCode, String memberName, Type[] parameterTypes, Object[] parms) in C:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:line 421   at ASCOM.DriverAccess.Telescope.SlewToCoordinatesAsync(Double RightAscension, Double Declination) in C:\ASCOM Build\Export\ASCOM.DriverAccess\Telescope.cs:line 1048   at Castle.DynamicProxy.AbstractInvocation.Proceed()   at Castle.DynamicProxy.AbstractInvocation.Proceed()   at NINA.Equipment.Equipment.MyTelescope.AscomTelescope.<SlewToCoordinates>d__147.MoveNext() in E:\Projects\nina\NINA.Equipment\Equipment\MyTelescope\AscomTelescope.cs:line 02022-05-23T22:05:56.2983|INFO|TelescopeVM.cs|SlewToCoordinatesAsync|877|Slewing from RA: 14:50:12; Dec: -29° 10' 33"; Epoch: JNOW to RA: 13:38:17; Dec: -29° 58' 52"; Epoch: JNOW2022-05-23T22:05:56.3920|ERROR|AscomTelescope.cs|SlewToCoordinates|703ASCOM.InvalidValueException:  set - '' is an invalid value. The valid range is: . ---> ASCOM.InvalidValueException: unspecified   at ASCOM.SynScanMobile.AscomConversationManager.Converse(Command command, ArgsChecker argsChecker, ConverseParams convParams)   at ASCOM.SynScanMobile.Telescope.SlewToCoordinatesAsync(Double RightAscension, Double Declination)   --- End of inner exception stack trace ---   at ASCOM.DriverAccess.MemberFactory.CheckDotNetExceptions(String memberName, Exception e) in C:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:line 552   at ASCOM.DriverAccess.MemberFactory.CallMember(Int32 memberCode, String memberName, Type[] parameterTypes, Object[] parms) in C:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:line 421   at ASCOM.DriverAccess.Telescope.SlewToCoordinatesAsync(Double RightAscension, Double Declination) in C:\ASCOM Build\Export\ASCOM.DriverAccess\Telescope.cs:line 1048   at Castle.DynamicProxy.AbstractInvocation.Proceed()   at Castle.DynamicProxy.AbstractInvocation.Proceed()   at NINA.Equipment.Equipment.MyTelescope.AscomTelescope.<SlewToCoordinates>d__147.MoveNext() in E:\Projects\nina\NINA.Equipment\Equipment\MyTelescope\AscomTelescope.cs:line 0

[Dale Ghent]

This has been a recurring issue with the SynScan driver The same issue with the SynScan driver was reported on the SharpCap forums in 2018, but with syncs:

https://forums.sharpcap.co.uk/viewtopic.php?t=1086

If your PC is using a locale that uses a decimal separator other than a period (such as 1,25 vs. 1.25) then this bug in the SynScan driver will get you. If that is your case, try switching your locale to one that uses a period as the decimal separator. NINA and any other ASCOM client and driver are expected to exchange floating point numbers in what’s called the “Invariant Culture”. This standardized culture communicates with the period being the decimal separator. However the SynScan driver seems to have issues with this because it is not set up to do so; instead it uses the local culture. This is why locales that use the comma as a decimal separator befall this issue.

[Healing Bench]

Hi Dale i'm in Australia, we don't use the European syntax’s of “,” so i don’t believe this is the trigger. I checked the windows 11 setup and it looks correctly set.

[Dale Ghent]

Well, it does seem to be some internal issue with SynScan. Here’s someone with the exact same issue, but from 2019 and using SGPro:

https://www.cloudynights.com/topic/685447-sgs-pro-failing-to-slew-to-target/

I downloaded the app and driver and installed it. The app can run in an emulation mode, so one doesn’t need to have a skywatcher mount to use it. I connected to the SynScan App Driver in NINA, and it connected to the app. I set the SyncScan App Driver to log by checking the Enable Logging checkbox in its configuration window before doing this. I went to Sky Atlas, searched for and slewed to M13, and I got the same error as you. There was no mention of the slew attempt in the log, indicating that the driver broke down before it had a chance to log the slewtocoordinates() command.

I then connected to the EQMOD simulator and did the same exercise. It “slewed” without a problem.

I connected my RainbowAstro RST-135. It’s a real mount. It too slewed to where it thought M13 was in the sky.

So far it’s SynScan nil and Everyone Else 2.

So I decompiled the SynScan ASCOM driver to see what it’s doing. I looked int the Converse() method where it’s dying. The code shows that it takes the command and its arguments, packages it up and sends it over the network to the SynScan App. The app responds with an error that triggers the InvalidValueException that NINA/you/I see. Whatever is croaking, is doing so in the app rather than the driver. Unfortunately the app is not something I can see the internals of, so it’s up to SkyWatcher to solve the rest of the mystery that, apparently, has been plaguing users for some time now.

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[Dale Ghent]

Well, good news. It seems that SkyWatcher has fixed it. I was using 1.19.12. You reported using 1.19.15. But on SkyWatcher GLOBAL’s website, they have a 1.19.19. I ran it instead and slewing works fine. Here is a direct link.

https://inter-static.skywatcher.com/downloads/synscanpro_windows_11919.zip

[Healing Bench]

Wow Dale, thanks for the great support. I had no idea there was an update to the driver, I’ll grab that and update my setup.

[Stefan B]

Thanks Dale for digging into it. Marking it as resolved

[Stefan B]

Removing version: 2.0 Beta (automated comment)