Schematics EL-3034 through EL-3039 show the layout for one each of the Opto-22 relay racks used in the instrument electronics. The sheets have a block in the upper left-hand area that associates a channel number and a bit number with a function. The channel number gives the location of the I/O module on the individual rack. The bit number gives the I/O bit that the software can read or write and the function tells what the bit toggles or reads.

In the lower left area is a pictorial representation of the actual I/O rack. The drawing shows where the relays are and what their function is. It also tells what relay should be plugged into each slot. Notice that between each relay and its screw terminal is noted what color relay should be installed. The other important piece of information shown here is the position of the various bus bars. These are Sheet metal strips that are used to connect from two to eight terminals together.

On the right-hand side of the drawing is a table showing the destination or the output connections of the I/O relays. The first column gives the I/O bit for programming. The pin column refers to the screw terminals on the edges of the relay racks. The next three columns give the connector and pin numbers that the output is connected to. The sixth column tells what relay part number populates each position on the relay rack. The last column tells the function that the relay controls. On the right-hand side of the table are the channel numbers as labeled on the board.

Grating Req1: I/O bit 49 is wired to the binary 0-Bit output of the pushbutton switch on the Grating manual pushbutton station. (More info)

Grating Req3: Bit 50 is wired to the binary 1-Bit output of the pushbutton switch on the Grating manual pushbutton station. (More info)

Grating Req4: Bit 51 is wired to the binary 2-Bit output of the pushbutton switch on the Grating manual pushbutton station. (More info)

Grating Hatch 1 Open: Bit 52 is wired to the limit switch which is activated when the Grating Hatch #1 door is opened to gain access to the Filter Wheel manual pushbutton station. (More info)

Grating Hatch 2 Open: Bit 53 is wired to the limit switch which is activated when the Grating Hatch #2 door is opened to gain access to the Filter Wheel manual pushbutton station.

Stop Gratings: Bit 54 is is wired to the STOP pushbutton stitches on the Grating Hatches (both) manual pushbutton station. When pushed, the software will halt the grating select stage motion. (More info)

Dewar Ion Pump Switch OK: Bit 55 is wired to the dewar ion pump's current/voltage front panel selector switch. When the selector switch is set to the 5KV position, the signal goes low. This tells the Galil controller that the current reading it receives via an analog input is accurate and is the normal operating position. (More info)

Vessel Ion Pump Switch OK: Bit 56 is wired to the dewar ion pump's current/voltage front panel selector switch. When the selector switch is set to the 5KV position, the signal goes low. This tells the Galil controller that the current reading it receives via an analog input is accurate and is the normal operating position. (More info)

Slit Cassette Closed: Bit 57 is wired to one of the two limit switches that are mounted of the side of the slitmask cassette. It is actuated when the cassette door is opened. (More info)

Slitmask In Place 2: Bit 58 is wired to one of two optical slotted switches located on the side of the slitmask frame. It is the one furthest from the cassette mechanism and thus the second one to activate as a slitmask is pushed into the form. (More info)

Slitmask Misaligned: Bit 59 is wired to the optical slotted switch located on the cassette door of the slitmask stage. It is activated by a vane attached to the 'comb' that is pulled into alignment when the slitmasks are all aligned correctly. (More info)

Slitmask In Place 1: Bit 60 is wired to one of two optical slotted switches located on the side of the slitmask frame. It is the one closest to the cassette mechanism and thus the first one to activate as a slitmask is pushed into the form. (More info)

Slitmask Aligned: Bit 61 is wired to the output of the slitmask aligned sensor. This sensor consists of a LED emitter and phototransistor receiver. The LED shines through a small round alignment hole that is cut into each slitmask. If the holes, and thus the slitmasks, are aligned then the receiver is activated causing the output to go low. (More info)

Slit Foot Retracted: Bit 62 is wired to a limit switch that is mounted at the rear of the pneumatic Bimba cylinder the inserts and retracts the slitmasks in and out of the slitmask form. When the piston is in the full retracted position the switch is activated and the signal goes low. (More info)

Slitmask Insert Out: Bit 63 is wired to the Bimba limit switch that is mounted at the rear of the pneumatic cylinder. When the piston is in the fully retracted position the switch is activated and the signal goes low. The second set of contacts on this switch is wired in series with the slitmask servo motor and cuts off power if the piston is not fully retracted. (More info)

Slitmask Insert In: Bit 64 is wired to the Bimba limit switch that is mounted at the front (end closest to the slitmask form) of the pneumatic cylinder. When the piston is in the fully deployed position the switch is activated and the signal goes low. (More info)

Slitmask Door Open: Bit 65 is wired to the limit switch which is activated when the Slitmask Hatch is opened to gain access to the Slitmask manual pushbutton station. (More info)

Slitmask Stop: Bit 66 is wired to wired to the STOP pushbutton switch on the Slitmask manual pushbutton station. (More info)

End Of Travel: Bit 67 is wired to the optical slotted switches located on the very end of the slitmask frame. It is activated when a slitmask is pushed all the way into the form. (More info)

Bit 68 (not used)

Grating Clamp Pin: Bit 69 is wired to a limit switch that is mounted behind the Grating clamp pin and is activated when the clamp pin is pushed into place. The clamp pin can only be pushed in if the current grating is in it's correct location. The pin is pushed in by grating clamp #2. (More info)

Slitmask Unload Req: Bit 70 is wired to the unload button on the Slitmask Pushbutton Station. Pushing the button causes the software to move the slitmask cassette into the load/unload position for changing masks. (More info)

Dewar Ion Pump OK: Bit 71 monitors a 120V AC relay. The relay is wired to the 120V of the ion pump controller which is present only when the controller is on. (More info)

Vessel Ion Pump OK: Bit 72 is monitors a 120V AC relay. The relay is wired to the 120V of the ion pump controller which is present only when the controller is on. (More info)