Simplified Drawing

The Grating Pushbutton Station is used to manually move the grating stage into the grating load position. The station consists of two separate boxes with controls to move the stage or stop the stage movement. At this time, only box 2 is active due to the fact that the third grating (labeled 'Position 5' above) has not been implemented. At the right hand side of the green box is the Station Enable switch. This switch is a DPDT limit switch that is actuated by opening the grating access door. Once actuated, +5V is applied to and turns on the yellow ENABLED LED. At the same time, the controller software will signal the control computer that the stage is under manual control. The red STAGE IS MOVING and green IN POSITION can then be turned on by the controller software to indicate the status of the stage. If no button has been pushed, the green LED should be on indicating that the stage is in an ordinal position. At this point the software polls the POSITION 3 and POSITION 4 pushbuttons via signals *REQ3 and *REQ4. If one of the pushbuttons is pushed the controller moves the desired grating into it's unload position. Note: during these manual moves all limits are still in effect. If the operator detects a problem while the stage is moving they can press the STOP button to signal the controller to terminate the movement. The operator should be aware that this is a software controlled move and if the controller or some link in the signal chain fails that the proper response is to allow the stage to move into it's secondary limit. The hope is to maintain the safety of the operator - when the stage hits the secondary limit the power will be removed from the stage motor.
Under software control the red STAGE IS MOVING LED will be turned on until the stage comes to a complete stop and the green IN POSITION LED will turn on. Once the grating has been changed, closing the access door will notify the controller software that the stage control is ready to be released back to the control computer

 

Sheet2:

 

Simplified Drawing

Sheet 2 shows the wiring, connector, and bit assignments for the pushbutton station.