Moravian Gx Camera ETH Adapter Mini for GX Cameras

Gx Camera Ethernet Adapter - Mini Version

The 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). The 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).

Gx series of CCD cameras are equipped with USB 2.0 interface with 480 Mbps transfer speed. USB interface brings numerous advantages beside the very high transfer speed. For instance USB connectors and cables contain also lines dedicated to provide power to attached devices, so the G0 and G1 cameras are connected to the host computer only by single cable (power requirement of the cooled CCD cameras of G2, G3 and G4 series is significantly greater than the USB line can provide and these cameras use their own power supply). USB cables are standardized, which is why they cannot be confused and plugged the wrong way etc. Also software support of USB devices is designed from the ground up to provide “Plug-and-Play” experience. Users need not to perform any device configuration, assign unique addresses etc.

A disadvantage of USB connection is the limited distance between a host PC and USB device. The maximum length of single USB cable is limited to 5 meters. This distance can be prolonged to 10 or 15 meters with the help of so-called Active USB Extenders, but a cable connection and active USB repeater (hub) must be placed every 5 meters. Very long USB connections can be also power-limited. The energy, provided by the host PC, is consumed by active repeaters and also long power lines with non-zero electrical resistance cause drop of supply voltage.

The problem of connection of Gx CCD cameras over a long distance is solved by Gx Camera Ethernet Adapter, offering remote camera connection over Ethernet interface. The core of the adapter is an embedded computer with a software is placed on the local flash storage.

Three models of the Gx Camera Ethernet Adapters are available:

The largest “standard” variant uses a PC-compatible motherboard equipped with the Intel Atom processor. No moving parts are present in the device, the processor needs no fan and is cooled only passively. This variant is powered by single 12 V DC line, the same like the G2, G3 an G4 cameras. Also power line connectors are the same, so the device can be powered like the rest of the setup.

Medium variant of the Gx Camera Ethernet Adapter called “mini” is also based on the PC-compatible motherboard, but a smaller one called NUC (an abbreviation from Next Unit of Computing). These motherboards can have higher computational power and thus also higher TDP, so they are equipped with a small cooling fan. The mini-variant of the adapter is powered by a 19 V DC adapter (similarly to many laptop and notebook computers), supplied with the device.

The smallest “micro” variant of the Gx Camera Ethernet Adapter is based on the ARM architecture. It is powered from a single 12 V DC line, like the standard variant (and like all G2, G3 and G4 cameras).

Common features

Regardless of different processors and in the case of Micro variant also different processor architecture, all devices employ multiple cores and at last 1 GB of on-board memory to be able to comfortably store full frames from even in the case all four connected cameras are the ones with the largest-resolution available. This is important to for the network connected device, because no isochronous data packet transfer and no delivery time can be guaranteed over a general network. Also all devices use the same software stack and are completely software compatible from the driver point of view.

The used Ethernet interface supports both 1 Gbps and slower 10/100 Mbps transfer speeds and it can be connected to all common local area networks. If the 1 Gbps interface is used and the download operations from multiple cameras do not overlap, the difference between download time of directly USB connected camera and camera connected over the Gx Camera Ethernet Adapter is negligible.

Configuration is performed through WWW interface and any web browser can be used to access it. The WWW configuration interface is not available all the time the device is running, it is stopped after two minutes from the time the device is powered up from the security reasons. This measure prohibits unwanted configuration changes when the device is accessible from many different computers.

Camera connection

Single Gx Camera Ethernet Adapter can attach up to four G0 to G4 cameras to the control PC using the Ethernet interface. It is worth noting that the device is not an ordinary USB/Ethernet converter, just tunneling USB data over the TCP/IP network (such converters usually do not work properly with all devices and their usage brings numerous problems and is not reliable). The Gx Camera Ethernet Adapter handles attached Gx cameras the same way like the host PC, there is no difference from the camera point of view in command sequences and especially timing, transfer speeds etc.

Quite opposite situation is on the control PC. There are fundamental differences between the camera connected directly to the USB port and the camera connected through the Gx Camera Ethernet Adapter. Cameras behave like two totally different and incompatible devices – the USB interface is used in the first case, TCP/IP network sockets interface in the second case (Gx camera and the Gx Ethernet Adapter behaves like a single device).

No USB device system drivers are to be installed on the control PC in the second case (and also system drivers for any other device are not installed), USB interface is not used to communicate with camera at all. The control computer communicates with the camera using the TCP/IP protocol only.

This is also why drivers for client programs (SIPS, ASCOM, MaxIm DL, …) are also different and a driver intended for camera connected to USB does not work with camera connected over Ethernet.

Let us note that unlike USB, the Ethernet interface (and TCP/IP network) is not designed to be “Plug-and-play”. If the connection to different computer (server) is to be established, its IP address or domain name must be known. So even before the control computer can connect to the Gx Camera Ethernet Adapter, the IP address or domain name of the particular device must be defined.

For instance every attached USB camera is immediately displayed in the SIPS (Scientific Image Processing System) software Camera configuration tool window and the user may choose the camera as imager or guider. And when no USB camera is connected, SIPS does not offer such cameras despite the camera driver is present and active.

On the other hand, cameras with Ethernet interface require the possibility to configure the IP address or domain name. This is why when the driver for cameras connected over the Ethernet is present in the SIPS, the software always displays a line “Gx Ethernet Adapter”, marked as “unconfigured”. When this line is selected, it is possible to open a dialog box allowing definition of IP address or domain name by clicking the “Configure” button.