Drive System

The electronics for the building drive has been mounted on a customized frame. Currently the drive system is being programmed to implement the basic tasks of accepting an analogue input control signal and turn the motors. The new drive will directly replace the old electronics. The old drive system will be removed from its rack and the rack modified to allow space for the slightly wider modules of the new system. The various control lines to the TCS will be connected and the motors swapped. It has been checked that the new motors have an identical mounting flange and drive shaft dimensions to the old ones.

A service engineer from Siemens will come at the beginning of December. He will check that our wiring and mounting arrangement meets safety and electrical requirements and then advise on the best programming philosophy and examine our proposed actual installation at the telescope. If this goes as planned we can decide when to change the system. Replacing the whole drive system is expected to take a full day, after which some tuning will be necessary for the system to work properly. As on earlier occasion, we will leave most of the existing system in place such that we can go back to the old system if need be. In principle the changeover is foreseen for the coming spring. To allow time for the fine tuning and to be on the safe side, the change will be scheduled before a technical night.

Thomas Augusteijn 2009-01-15