CH Tech Pulse Generator - Manual (Page 25)

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5.0 TROUBLE ANALYSIS
5.1
BUILT IN TEST AND DIAGNOSTICS
Built in test functions are provided for the VX462B in the form of read back registers. The
VXIbus registers perform as defined in the VXIbus specification and the timing and control
registers have read back capability for data verification and test.
5.2
TROUBLE ANALYSIS GUIDE
The first approach to troubleshooting is to attempt a A16 VXIbus access. A successful access
(read or write) will not produce a bus error. If a bus error occurs, a probable cause is an
improperly set logical address. Check this setting and verify the program for proper addressing.
If no bus error occurs, read the first two VXIbus registers. The expected device type is 'FFFD',
and the expected ID is 'FFC1' (refer to the paragraph 3.5.1 for the Device Type and ID bit
locations).
To check the register write capability, write a value to the Pulse Width Register, then read it back.
The returned value should match the data written with the exception of the unused bits. If the
module is responding as expected, program a pulse stream and monitor the Pulse Out with an
oscilloscope. If no signal is seen or is not as expected, utilize the modules read back capability to
verify that all registers are correctly set. When diagnosing output problems, isolate the module
from external loads by removing the connector.