Troubleshooting Procedures,
Checking for a B-tap Problem
Checking the Power Supply
If the Power Supply is
supplying +28V
Checking for Completion of
Standard Slave Initialization
Continued
The measured voltage at the B-tap output terminals on the Power I/O Interface
board should be 28.5V ±.2V. If the B-tap is not the correct voltage there is
probably a power initialization problem.
If only the four basic boards are installed in the system:
(Master Controller, Standard Slave, Power I/O Interface and Power Supply),
check the Universal Switcher Power Supply for proper operation first --
although statistically, this has the least likelihood of being bad. (see 'Checking
the Power Supply', below)
If the green Power I/O Interface board LED is lit, check for approximately
28.5V on the red & black leads connected to the supply. If 28.5V is present, the
power supply can be assumed to be OK.
If +28V is measured at the output of the Power Supply , perform the following
checks:
• Check the Power IO Interface / Standard Slave interface ribbon cable for
proper connection.
• Check the Power I/O enable jumpers.
• Check for proper Standard Slave/Power IO initialization.
The three Power I/O Interface taps are all controlled by the Standard Slave
microprocessor. There are a series of tests that the software performs before the
taps are turned on. Refer to Table 5-1 (page 5-1) for the software initialization
sequence.
The last step performed before the Standard Slave begins preparing for
communications with the Master Controller is to turn on the +36V Mapnet
voltage. Measure the Mapnet channel voltage on the Standard Slave. If there is
approximately 36V present, the Standard Slave software has successfully gone
through the initialization process and the Power I/O Interface board can be
assumed to be good.
4-5
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