Ethernet to multi-CAN gateway for VLT MOONS instrument control

The MOONS instrument is a new Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope (VLT) . The instrument design aims to deploy nearly 1000 fibers over the field of view requiring to control nearly 2000 actuators by the same number of CAN bus stepper motor drives through 15 independent CAN bus networks. All this massive traffic and extensive wiring can be merged down into a single Ethernet line by means of 3 Ethernet to Multi-CAN Gateways (EtherCAN) and an Ethernet switch. This is possible today due to emerging multi-CAN ARM microcontrollers, which provide highly embedded solutions suited to be located closer to the sensitive areas of the instrument, where power dissipation and space are critical.