New hardware support

Support for new devices like Gx Cameras with Ethernet Interface and implementation of ASCOM interfaces for cameras, filter wheels, focusers, telescope mounts and observatory domes are the most important enhancements of SIPS version 2.2.

Gx Camera Ethernet Interface

Gx Camera Ethernet Adapter allows connection of Gx series cameras (models G0 to G4) to the control computer using Ethernet interface and TCP/IP protocol stack (this means over Local or Wide Area Networks). Single Gx Camera Ethernet Adapter contains four USB 2.0 ports and allows connection of up to four Gx cameras at the same time (regardless of the specific series, cameras can be freely combined).

Due to differences in G0/G1 and G2/G3/G4 camera features, there are two different drivers for these series of cameras connected through USB interface. But when these cameras are connected over the TCP/IP, the Gx Camera Ethernet Adapter firmware handles all the different features and there are no significant differences for the control computer. This is why a single driver for all Gx cameras with Ethernet interface exists.

The Gx Camera Ethernet Adapter hardware and configuration is described in detail here.

ASCOM devices

ASCOM standard defines interfaces between control software running on a PC and various hardware devices, used to run astronomical observatories. This unified software layer thus allows usage of various devices without the necessity to implement native driver for every software package. The benefits are obvious and important—development and support cost is significantly reduced (it is enough to write single ASCOM driver instead of many drivers with different proprietary interfaces for every software package) and also reliability is higher (it is easier to properly implement and debug one driver compared to many drivers for single device, often maintained individually).

ASCOM standard covers many different devices. SIPS v2.2 supports the following ones:

• Cameras and Filter Wheels: SIPS handles both cameras and filter wheels as single integrated devices, which is why both ASCOM cameras and ASCOM filter wheels are configured in the CCD Camera tool. Still, ASCOM handles both cameras and filter wheels individually, which is why configuring of ASCOM camera in SIPS opens a dialog box, which allows setting up of both ASCOM camera and ASCOM filter wheel.

  

  ASCOM Camera and ASCOM Filter Wheel configuration

While SIPS supports connection of multiple cameras at once, other devices can be connected only in one instance. This is why available devices are offered only as a drop-down list (combo box) with two buttons for configuration and re-enumeration of all connected devices .

• Focusers: ASCOM focusers can be configured in SIPS Focuser tool.

  

  ASCOM Focuser configuration

  When a focuser is connected, other functions in SIPS are available, like automatic focusing, refocus on filter change (providing filter offsets are defined) etc.

• Telescope mounts: ASCOM mount driver is added to already existing Celestron NexStar and Meade LCX200 protocol drivers.

  

  ASCOM Telescope mount

• Observatory dome: ASCOM Observatory dome allows control of domes or roll-off roofs from the SIPS environment.

  

  ASCOM Observatory dome

G1-1200

Support for new automatic guiding and planetary camera G1-1200 with high quantum efficiency Sony ICX445 CCD detector was added. G1-1200 guider is described here.

Driver configuration

SIPS uses the 'sips.ini' configuration file, placed in the same directory like the 'sips.exe' executable file, to load device drivers. If the driver has to be used by SIPS, it must be defined in 'sips.ini' file. This ini file was extended in version 2.2 to include all new drivers.

[Camera]
g1ccd = g1ccd.dll
g2ccd = g2ccd2.dll
g3ccd = g3ccd.dll
Gx Camera on Ethernet = gxetha.dll
ASCOM Camera = ascom_camera.dll

[GPS]
Garmin USB = gps18.dll
NMEA = nmea.dll

[Telescope]
NexStar = nexstar.dll
LX200 = lx200.dll
ASCOM = ascom_tele.dll

[Focuser]
ASCOM = ascom_focuser.dll

[Dome]
ASCOM = ascom_dome.dll

It is possible to edit this file to contain only drivers used by particular observing setup. Unused drivers can be moved to arbitrary section name, which is skipped by SIPS. For instance if only G2 and G1 USB cameras are used, this file can be modified as follows:

[Camera]
g1ccd = g1ccd.dll
g3ccd = g3ccd.dll

[_Camera]
g2ccd = g2ccd2.dll
Gx Camera on Ethernet = gxetha.dll
ASCOM Camera = ascom_camera.dll

...

The [_Camera] section is not recognized by SIPS, so all drivers in this sections are skipped (not loaded and initialized).

When the Gx Camera Ethernet driver is configured (its IP address is defined) and the device itself is not connected to the network and/or not switched on, skipping its driver can save approx. one second of startup time, for which the driver waits for connection. Only after the attempt to connect to the device fails on timeout, initiation sequence continues.

New features

SIPS v2.2 was enhanced with several new features, beside the new hardware support.

Adjusting to High-DPI displays

Using of high-resolution displays of relatively small physical dimensions leads to shrinking of displayed GUI elements to sizes hardly distinguishable and texts becomes almost unreadable. Windows offers enlarging of “screen density”, expressed as DPI (dots per inch), from default 96 DPI do higher values of 120 DPI (125%), 144 DPI (150%) or other user defined values. The only effect of higher DPI is enlarging of the fonts used on screen. Font size is defined in so-called points (abbreviation “pt”), which is a device-independent unit. E.g. 12 pt font should have the same physical size regardless if printed on 300 DPI or 1200 DPI printer. It is up to the application to update the size of GUI elements to take greater pixel size of all texts into account .

SIPS v2.2 added adjusting of its GUI elements to higher DPI screens (and larger fonts used).

Adding filter offset information

Because there is no way how to determine the actual filters in the filter wheel automatically, the camera driver reads the 'g3ccd.ini' file to determine actual configuration of filters, which will be then reported to the SIPS. The 'g3ccd.ini' file is placed in the same directory where the actual driver files (especially the 'g3ccd.dll' library) are installed. This file is ordinary text file following the .INI files conventions.

If multiple cameras handled by the same driver are used, it is possible to include camera ID into the file name, e.g. 'g3ccd.2158.ini' will be used for camera ID=2158 only (note leading zeros are not allowed in the ID). Driver searches for the ID-specific file name first and only if it is not found, it tries to open generic ini file name.

Here is the example of the 'g3ccd.ini' file:

[filters]
Luminance, Gray, 660
Red, LRed, 660
Green, LGreen, 660
Blue, LBlue, 660
Clear, 0, 0

Filters are described in the [filters] Section. Every line in this section describes one filter position. Filter description is a comma-separated list of three values:

• Filter name: This name is returned to the client application, which can use it to list available filters in the filter wheel.

• Filter color: This color can be used by client application to display the filter name with a color, hinting the filter type. The color can be expressed by a name (White, Red, LRed, etc.) or directly by number representing the particular color (0 represents black).

• Filter offset: Distance to move the focuser to refocus upon filter change. Plan-parallel glass shifts the actual focus position back for 1/3 of the glass thickness (exact value depends on the glass refraction index, but for almost all glasses 1/3 is very close to exact value). Refocusing is useful when changing filters of different thickness among exposures or when some exposures are performed through filters and other without filters at all.

Filter offsets can be defined in focuser dependent steps or in micrometers (μm). If the micrometers are used, it is necessary to inform driver by the MicrometerFilterOffsets parameter in the [driver] section of the ini file.

[driver]
MicrometerFilterOffsets = true

[filters]
Luminance, Gray, 660
...

If micrometers are used and the particular focuser driver provides information about the size of single step, SIPS is the able to calculate necessary steps to move focuser to refocus properly. Refocusing upon filter change can be switched on in the CCD Camera tool (see the image in the above section).

Other enhancements

Other enhancements touched various parts of the SIPS:

• Driver for G0 and G1 camera now offers binning up to 4 × 4 pixels.

  Hint:

  When a camera without binning support is used as guider, SIPS still offered binning and implements this function in software. But G0/G1 camera used as main imager did not allow binning and if binning was required, explicit software binning had to be chosen in the New Images Transform SIPS tool.

• CCD Camera tool offers the possibility to refocus upon filter change, providing individual filter offsets are defined and focuser driver is defined and online.

• Autofocus feature of the CCD Camera tool was enhanced to be more robust.

• When a GEM mount is used inside the dome, dome slot is often too narrow to provide enough opening for the scope regardless of the tube-to-pier orientation. So it is necessary to shift the dome slot azimuth depending on the telescope coordinates and OTA position to the pier (east or west). SIPS v2.2 added exact analytical calculation of the dome slot azimuth correction. Necessary parameters are defined in the GEM and Dome Parameters dialog box.

  

  GEM mount and dome parameters definition

Bug fixes

The following problems were fixed:

• Definition of exposure series in the Series tab of the CCD Camera tool required hitting the Enter key after each parameter was defined, just clicking another cell was not enough. New version fixes this problem.

• NexStar protocol requires switching off of the tracking before GoTo command is issued (or generally any movement faster then the lowest guiding speed). NexStar protocol driver sampled the mount tracking only upon startup to correctly restore the tracking after GoTo (tracking is North, South of Off). The problem was when SIPS was launched and NexStar initiated before the telescope was aligned, which means in time the mount tracking was Off. Then any move resulted to restoring of the Off tracking state. New driver version samples the Tracking before each move command is issued.

SIPS v2.2 is a freeware and can be downloaded from the download section of this WWW site.