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The Magdalena Ridge Observatory Interferometer (MROI) Beam Relay System (BRS) comprises a network of airevacuated pipes and relay stations, consisting of a pier and vacuum can containing a relay mirror, shear alignment sensors, and control electronics. Located at precise points along the arms of the interferometer array, the BRS piers contain remotely controllable mirrors which can be precisely adjusted to direct light from the adjacent unit telescope down the beamline and into the Beam Combining Facility (BCF), where interference fringes are made. Changing the array configuration is a planned function of interferometer operation, but is time consuming and complicated, as it will involve moving mirror assemblies between the vacuum cans (VC). The Vacuum Can Hub (VCH) is a network Modbus message processor and instrumentation hub that connects the Vacuum Can (VC) instrumentation to the MROI power and communication infrastructure via a single Power over Ethernet (PoE) access point. This greatly simplifies and speeds up array reconfiguration. In this paper we shall discuss the MROI Automated Alignment System (AAS), which is tasked with ensuring precise alignment of beamlines connecting the UTs with the BCF, and its role as supervisor of the VCH. We also discuss the BRS components interfaced by the VCH: first, the VC 1-wire temperature sensor network, whose data is used by the AAS for driving fine adjustments of the BRS relay mirrors via the AAS’s feed-forward open-loop thermal mechanical model. Second, twin shear sensors used for coarse beam alignment, each consisting of custom designed 10 × 10 pixel photodiode arrays, whose electronics and software allow direct access by the AAS by using the VCH’s message routing capabilities. The VCH’s ability to translate and relay Modbus messages between the network and serial domain allow high flexibility in defining the quantity and types of BRS hardware that can be installed in VCs.
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