Miscellaneous Drawings

Tester and Simulator For Shutter Controller, EL-1233

SCHEMATIC: schematics/MULTIPURPOSE/EL-1233.sch.pdf
Page last updated: May 14, 2002

Overview

This is a hand paddle that can be used to verify the proper operation of the shutter controller (EL-1183) or to trouble shoot faulty operation. Depending on how it’s connected, it can be used to simulate the CCD Controller system, the shutter itself or both.

Connections

The tester, itself, has a 20-pin IDC connector that carries all functions. The cable attached to it fans out to three other connectors; two MS style connectors, a 7-pin and a 5-pin, and one that is either a 10-pin IDC or a 15-pin D-sub. All three connectors go to the shutter controller box.

Operation

Inside the tester, the 7-pin MS connector goes to two pairs of red & green LED’s connected in parallel, back-to-back that indicate the direction of current flow sent to the air piston solenoids. The polarity to open a shutter blade lights the green LED and the polarity to close a shutter blade lights the red LED. A light will flash briefly indicating the current that would have activated the air piston solenoid.

The 5-pin MS connector goes to two center-off toggle switches which simulate the air piston limit switches. (The center-off function allows simulating a shutter blade that is in transition or has gotten stuck between its open & close positions.) These should be set to reflect the state the blades would be in according to which solenoid light flashed. For example, if the left-open light flashed, the left limit switch should then be set to the open position.

Together, the functions of these two MS connectors comprise the "stage simulation" part of the tester. If either of them is used, the other should be used also.

The 10-pin IDC (or the DB-15) connector goes to the "controller simulation" part of the tester. The four LED’s represent the air piston limit switch information being sent back to the controller. Their state should match that of the LED’s on the shutter controller itself. The two "shutter status" LED’s shown in the schematic are not implemented on some of the testers.

When the push-button switch, S1, is pressed, it turns off the transistor allowing the "open/close" command line to go high, telling the shutter controller to open the shutter. The shutter will stay open only as long as the switch is pressed. Releasing the switch turns the transistor on, pulling the command line to ground thus telling the controller to close the shutter.

Usage

The two sections of the tester can be used separately or together depending on what type of tests are needed. Used together, the shutter box itself can be tested, acting both as CCD controller and as the shutter mechanism. Is that mode, care should be taken to "coordinate" the command push button and the limit switches. For example, if the command push button is pressed and the left-open solenoid light flashes, the button should not be released until the left limit switch is moved to the open position. Upon releasing the push button, the right-close light will flash and the right limit switch should be moved to the closed position.

If just the CCD controller section is plugged in, and the shutter mechanism is attached to the shutter controller by the MS connectors, the tester acts as a manual control allowing the shutter to be opened and closed. The limit feedback lights show what is happening with the shutter.

If the MS connectors of the tester are connected to the shutter controller and the CCD controller is connected to the shutter controller, then the CCD controller can run the shutters and the results can be monitored at the tester. This mode also allows error conditions to be simulated to test the CCD software. For example, if the CCD controller commands the shutter to open and the limit switches on the tester are not moved, the effect would be to simulate that the air piston was stuck and that the CCD software should not start the exposure it had intended to start.