MaxStep & MaxIncrement in FSUSB ASCOM Driver
Posted: Mon Aug 15, 2022 2:11 pm
I purchased a USB Focus Motor Controller hoping to use it for autofocus via the widely used N.I.N.A. imaging platform. I encountered issues loading the FSUSB ASCOM driver (which are described below in case anyone is interested). I did find a couple of workarounds but in both cases have the following problem: N.I.N.A. sees a "Max. increment" and "Max. step" of 1000. This means that total range of travel is limited to 1000 units which is far too small for autofocus where something like 50000 would be more appropriate. When the FSUSB ASCOM driver is connected the ASCOM Device Hub that is part of the standard ASCOM platform distribution it also shows static properties of Maximum Increment: and Maximum Step: as being 1000. I don't know if these are specified in the driver or are ASCOM defaults when no values are specified but is there a way to have them increased? I've tried adding new keys in the ASCOM Profile Explorer but that doesn't help.
Problems and workarounds loading the FSUSB ASCOM Driver in N.I.N.A.
Attempting to load the FSUSB ASCOM driver with 64-bit N.I.N.A. results in a COM Class error which typically happens for 32-bit drivers. It also fails in SharpCap. The driver will load in the depreciated 32-bit N.I.N.A. but with the range limitation of 1000 described above. To load the FSUSB ASCOM Driver 64-bit N.I.N.A. first connect it to the ASCOM Device Hub and then connect N.I.N.A. to the Device Hub Focuser. This again has the same range limitation. There is another possibile workaround described here https://techtalk.gfi.com/32bit-object-6 ... vironment/ which I haven't tried. In 2013 there was some discussion of a combination 32/64-bit driver FSUSBCombo which I downloaded. It also failed to load under 64-bit N.I.N.A. giving a BadImageFormatException.
Problems and workarounds loading the FSUSB ASCOM Driver in N.I.N.A.
Attempting to load the FSUSB ASCOM driver with 64-bit N.I.N.A. results in a COM Class error which typically happens for 32-bit drivers. It also fails in SharpCap. The driver will load in the depreciated 32-bit N.I.N.A. but with the range limitation of 1000 described above. To load the FSUSB ASCOM Driver 64-bit N.I.N.A. first connect it to the ASCOM Device Hub and then connect N.I.N.A. to the Device Hub Focuser. This again has the same range limitation. There is another possibile workaround described here https://techtalk.gfi.com/32bit-object-6 ... vironment/ which I haven't tried. In 2013 there was some discussion of a combination 32/64-bit driver FSUSBCombo which I downloaded. It also failed to load under 64-bit N.I.N.A. giving a BadImageFormatException.