Envision Peripherals NV3128 User Manual
Page 79
NV3128 RS-422A Machine Control Data Routing Switch
5-5
SIGNAL PATH
The quickest way to isolate problems in a single connection is by module
substitution. If sufficient spares are not available to carry out this strategy,
the next best recourse is path substitution:
1. Route the problem signal to a new crosspoint/output address.
2. If new route does not correct the problem, the source port circuitry is
probably faulty. Verify by reconnecting the source machine to a new port,
or by swapping the two I/O modules. The upper of the two I/O modules
supports ports 1-64. The lower module supports ports 65-128. Do not
overlook the possibility of a problem in the external cabling or equipment.
3. Assuming the new route of Step 1 passed signal, route any signal to the
problematic output with the I/O cards swapped. Signal passes? Then the
I/O module is defective. No Go? The crosspoint module is at fault.
MAPPING AND COMMAND PROBLEMS
Most switch problems result from the complexity of the control system
interface. Refer to section 3 (older systems) or the UniDiag manual (newer
systems) for a discussion of the PC-based diagnostic and control utilities
furnished with the routing switch.