AGFA Avantra 36/44 Service Manual page 96

• Supply Motors Test– to test the motors, the supply DAC is set to 500
millivolts and one of the motors under test is selected by addressing it via
port C. The supply motor DAC controls four motors:
• Supply punch
• Supply spindle A and B
• Supply cassette
The test verifies that the MOTORON bit gets asserted low, by reading the
sensors. If MOTORON is not asserted within 20 milliseconds, an error is
reported. The motor is then de-selected. The test verifies that the
MOTORON bit gets asserted high, by reading the sensors. If MOTORON
bit does not go high within 20 milliseconds, an error is reported.
• Take-up Motors Test– to test the motors, the take-up DAC is set to 500
millivolts and one of the motors under test is selected by addressing it via
port C. The take-up motor DAC controls three motors:
• Take-up punch
• Take-up nips
• Take-up cutter
The test verifies that the MOTORON bit gets asserted low, by reading the
sensors. If MOTORON is not asserted within 20 milliseconds, an error is
reported. The motor is then de-selected. The test verifies that the
MOTORON bit gets asserted high, by reading the sensors. If MOTORON
bit does not go high within 20 milliseconds, an error is reported.
• Video Data Path Test– The video data path is tested by inserting a known
data pattern at the video input, where it would normally be input from the
CGEN bus. The data is imaged with the laser beam disabled. An extra
shift register clocks out the test pattern. The video and the output of this
register are exclusive 'ORed.' Any unequal bits will cause an error to be
latched. The data pattern is generated in hardware and consists of 55's,
AA's and an incrementing pattern. A check is made for the proper amount
of gates per scan line.
• DAC Loop Backs– all the DAC generated signals that go off the board are
looped back to a single A/D input on the DEC K-4. The various signals are
summed. The signals not being tested must be set at 0 volts. Some of the
DACs are written by the DSP, others by the SPI master, either the DIAG or
the DEC micro-controller.
Section I: Imagesetter
Diagnostics 3-9