The diagnostic test set for the Topcon TRC-50VT retinal camera (fundus camera) allows you to diagnose and analyze electronic and timing problems in the interface between a retrofitted digital camera and the Topcon instrument. The test set contains all the electronics of the normal digital camera electronic interface cable, plus switches, test points, indicator lamps, and alternative isolation devices. The test set displays the status of the interface, while allowing you to test the interface in automatic operation, or manually control the features of the interface.

The diagnostic test set features the following status displays, controls, connections, and test points.

Status displays: The STATUS display lamps on the test set include the following:

• Topcon +V (green LED lamp): Illuminates steadily when Topcon DC supply power is present on the interface connections.

• Topcon Trigger (red LED lamp): Illuminates briefly when the Topcon joystick trigger button signal is received from the interface connections, which should in turn trigger the camera shutter release. May also show a less-bright steady illumination if the Topcon instrument delivers a steady voltage less than the trigger level.

Controls: The TEST controls on the test set include the following:

• FLASH (momentary pushbutton): Manually forces a fire of the Topcon flash via the interface connection, using a directly connected switch.

• SHUTTER DIRECT (momentary pushbutton): Manually forces a trigger of the camera shutter via the camera shutter remote connection, using a directly connected switch.

• SHUTTER ISOLATED (3-position toggle switch): Manually triggers the camera shutter via the shutter remote connection using the isolation device selected by the ISOLATION DEVICE switch. The three positions are:
  • TOPCON (upper position): Connects the Topcon joystick button signal to the selected shutter remote isolation device.
  • NONE: (middle position): Disconnects the isolated shutter control from any signals.
  • TEST: (lower position, momentary): Disconnects the Topcon joystick signal, and test triggers the isolated shutter control using internal battery power.

• BALLAST 1K and BALLAST 3K (2-position toggle switches): Applies ballast resistance (in ohms) to the Topcon joystick signal line. The IN (upper) position of the switch applies the indicated resistance of 1K ohms or 3K ohms. The OUT (lower) position removes any resistance. When these two switches are both IN, a net paralleled resistance of 0.75K ohms is applied.

• ISOLATION DEVICE (3-position toggle switch): Selects the type of isolation device between the Topcon instrument joystick signal and the digital camera shutter remote.
  • OPTO: An optoelectronic isolation device connects the Topcon joystick button to the Canon shutter.
  • NONE: Neither isolator is connected. The Topcon joystick button is disconnected from the Canon shutter. (Test points and indicator lamps on the test set remain connected, however.)
  • MECH: An electromechanical isolation device connects the Topcon joystick button to the Canon shutter.

Connections: The following cables connect the test set to the Topcon instrument and digital camera:

• Topcon upper-port connector: A 15-pin D-subminiature plug which mates to the 15-pin connector near the Topcon upper port. This connects the Topcon joystick button and the Topcon flash to the test set.
  

• Camera remote shutter: A Canon N3 and/or E3 connector for connection to the Canon digital SLR camera's remote shutter receptacle (photo shows N3 connector).
  

• Camera flash sync: A PC flash sync plug for connection to the Canon digital SLR camera's flash sync socket, which socket is either on the body of the camera (Canon models 40D, 5D, etc) or adapted via an adapter on the camera flash hot shoe (Canon Rebel models).
  

Test points: The following test points are provided for voltage readings with a voltmeter, if the user is so equipped. The Topcon interface, Canon cameras, and internal test set battery all operate with non-hazardous voltage levels.

• Topcon ground (green screw-post/banana 4-way jack): Chassis and signal ground for the Topcon instrument from the interface connection.

• TP-A (Test point A, white flush banana jack): The Topcon DC supply voltage from the interface connection.

• TP-B (Test point B, white flush banana jack): The Topcon joystick trigger signal from the interface connection.

Test N1:

• Connect three cables: one to the Topcon instrument (15-pin plug), and two to the Canon camera (remote shutter plug and flash sync plug).
• The Canon camera can be placed on the instrument table, and need not be mechanically mounted on the Topcon upper port adapter.
• Set the test set SHUTTER ISOLATED switch to TOPCON.
• SHUTTER ISOLATED is a 3-position switch; make sure it is not set in the middle to NONE.
• Set the BALLAST 1K and BALLAST 3K switches to OUT.
• Set the ISOLATION DEVICE switch to OPTO.
• ISOLATION DEVICE is a 3-position switch; make sure it is not set in the middle to OFF.
• Make sure the Topcon instrument and Canon camera are both turned ON.
• Set the Topcon flash intensity on the Topcon console to the lowest energy setting.
• Set the Topcon device selector on the Topcon console to UPPER (not LOWER, TV, or POLA).
• Press the Topcon joystick button and observe that the following occurs with each press:

  NORMAL UPPER-PORT EXPOSURE SEQUENCE:

  • The Topcon upper-port mirror-flip actuates.
  • The Canon camera shutter operates.
  • The Topcon flash fires.
  • The TOPCON TRIGGER lamp illuminates on the test set.

For these tests, the test set is operated stand-alone (disconnected from both the Topcon instrument and Canon camera).

Test S1:

• Select the SHUTTER ISOLATED switch to the TEST position momentarily, and observe the TOPCON TRIGGER lamp illuminating. This indicates the internal 9 volt battery voltage is good.
• You may also read the actual battery voltage with voltmeter probes between TP-A and TP-B while holding TOPCON TRIGGER in the TEST position.
• No lamp, or a voltage reading significantly below 9 volts DC at the test points, indicates the battery is either spent or disconnected.

Test S2:

• Repeat Test S1 while selecting the ISOLATION DEVICE switch in each of its three positions, OPTO, NONE, and MECH.
• The lamp illuminating in each case indicates the isolation device inputs and wiring are working properly.

For these tests, the test set is operated while connected to the Canon camera only, and disconnected from the Topcon instrument.

For all camera-only tests:

• Make sure that the Canon camera power is turned on during the following tests, and the camera battery is charged.
• Set the camera's "Auto power off" menu item to OFF (remotely operating the Canon shutter does not "wake up" the camera from sleep mode, if the sleep time elapses with no activity).

Test C0:

• With the camera on, insert the camera remote plug from the test set into the camera socket.
• Observe that the camera shutter does not operate when inserting the plug.
• Press the shutter button on the camera and observe that the camera shutter does operate.

Test C1:

• Press the SHUTTER DIRECT pushbutton momentarily, and observe that the Canon camera shutter operates for each such press.
• The TOPCON TRIGGER lamp does not illuminate for this test.

Test C2:

• Set the ISOLATION DEVICE switch to OPTO.
• ISOLATION DEVICE is a 3-position switch; make sure it is not set in the middle to OFF.
• Select the SHUTTER ISOLATED switch momentarily to TEST.
• Observe that the Canon camera shutter operates with each press of TEST.
• Observe that the TOPCON TRIGGER lamp illuminates with each press of TEST.

Test C3:

• Repeat Test C2 but with ISOLATION DEVICE set to MECH instead of OPTO.
• ISOLATION DEVICE is a 3-position switch; make sure it is not set in the middle to OFF.

For these tests, the test set is operated while connected to the Topcon instrument only, and disconnected from the Canon camera.

Test T0:

• Turn on the Topcon instrument.
• Connect the 15-pin D-sub plug from the test set to the upper-port receptacle.
• Observe that the green TOPCON +V lamp illuminates, indicating Topcon power.
• Leave the Topcon instrument on, and the 15-pin plug connected, for all the following tests.

Test T1:

• Set the SHUTTER ISOLATED switch all the way up to TOPCON.
• Observe that the red TOPCON TRIGGER lamp is not illuminated, or is only dimly illuminated.
• If the TOPCON TRIGGER lamp is dimly illuminated, move the SHUTTER ISOLATED switch to NONE, and observe that the lamp is no longer dimly illuminated.

Test T2:

• Set the Topcon flash intensity on the Topcon console to the lowest energy setting.
• Press the FLASH button momentarily and observe that it fires the Topcon instrument flash with each press.

For these tests, the test set is operated while connected to both the Topcon instrument and the Canon camera.

Test X0:

• Make sure that three cables from the test set are connected: one to the Topcon instrument (15-pin plug), and two to the Canon camera (remote shutter plug and flash sync plug).
• Set the test set BALLAST 1K and BALLAST 3K switches to OUT.
• Set the test set SHUTTER ISOLATED switch to TOPCON.
• SHUTTER ISOLATED is a 3-position switch; make sure it is not set in the middle to NONE.
• Make sure the Topcon instrument and Canon camera are both turned ON.
• Set the Topcon flash intensity on the Topcon console to the lowest energy setting.
• Set the Topcon device selector on the Topcon console to UPPER (not LOWER, TV, or POLA).
• Press the shutter button on the Canon camera, and observe that the Topcon flash fires with each press.

Test X1:

• Use the instrument, camera, and test set settings for Test X0 above.
• Set the ISOLATION DEVICE switch to OPTO.
• ISOLATION DEVICE is a 3-position switch; make sure it is not set in the middle to OFF.
• Press the Topcon joystick button and observe that the following occurs with each press:

  NORMAL UPPER-PORT EXPOSURE SEQUENCE:

  • The Topcon upper-port mirror-flip actuates.
  • The Canon camera shutter operates.
  • The Topcon flash fires.
  • The TOPCON TRIGGER lamp illuminates on the test set.

• If the above normal exposure sequence occurs, congratulations! Testing is successful and no further tests are indicated.
• If the normal exposure sequence fails to occur, proceed to the next test.

Test X2:

• Repeat Test X1, but with the ISOLATION DEVICE switch to MECH.
• ISOLATION DEVICE is a 3-position switch; make sure it is not set in the middle to OFF.
• If the normal exposure sequence still fails to occur, proceed to the next test.

Test X3:

• Perform this test if Test X2 fails, or the remote shutter otherwise appears to be stuck-on.
• Repeat Test X2 with BALLAST 1K in the IN position and BALLAST 3K OUT.
• Repeat Test X2 with BALLAST 3K in the IN position and BALLAST 1K OUT.
• Repeat Test X2 with both BALLAST 1K and BALLAST 3K in the IN position.
• If the normal exposure sequence still fails to occur, proceed to the next test.

Test X4:

• Perform this test if Test X2 or Test X3 fails, or the remote shutter otherwise appears to be stuck-on.
• Set SHUTTER ISOLATED to NONE.
• Set ISOLATION DEVICE to OPTO.
• ISOLATION DEVICE is a 3-position switch; make sure it is not set in the middle to OFF.
• Press the SHUTTER DIRECT button momentarily, and observe that the NORMAL UPPER-PORT EXPOSURE SEQUENCE of Test X1 occurs.
• If the normal exposure sequence still fails to occur, contact us for further instructions.