Barrel Electronics

The barrel electronics section of this manual contains descriptions of the barrel electronics for the DEIMOS Spectrograph. It corresponds to the Barrel Electronics tab in the electronics schematics binder.

The Interlock Monitoring schematic shows the limit switch wiring for the manual hatches on the barrel of the instrument. Three hatches are wired as shown above. This drawing shows only one pole of the actual DPDT limit switch that is mounted at the hatch. The poles shown here are wired to Galil controller #1 and are used to monitor which limit switch of the 3 hatches is actually open. The other pole of the switch performs the interlock function for the barrel rotation stage. That pole of each of these switches are wired in series so that if any one of them are open the interlock line will open, dropping out the interlock relay which is in series with the rotation motor. The control computers will be informed via the rotation controller if any of the hatches are open and prohibiting rotation but the control computer must interrogate these I/O bits to determine which hatch(es) is open. This layout of the I/O was used in an attempt to keep the number of cables in the cable wrap to a minimum. More information on the rotation stage and interlocks, see EL-3120.