Communications Failures - IBM 6400 Maintenance Information Manual

Communications Failures

Many host-printer communications problems are complex. With the exception
of a defective interface cable, most communications problems are not a result
of a hardware failure. They usually result from an incompatible configuration
of the host computer system, network (LAN, print server, controller,
multiplexer, etc.), or the printer. Sometimes the print application program itself
is at fault.
If you have limited communications background experience, and the cause of
the problem is not readily apparent, do the following:
1. Print out the printer configuration.
2. Obtain a copy of the Device Host Configuration if possible.
3. Call your support group for assistance in problem analysis.
If you cannot obtain support, or you have previous experience solving host-
printer communications problems, the following additional information is
provided.
You can quickly check the ASCII portion of the printer logic by sending a plain
text file from a PC to the printer via the parallel or serial port. For a description
of each of the ASCII interfaces, refer to the Setup Guide.
Problem
Fails to print from host
-or-
Prints incorrect characters
-or-
Prints extra characters
-or-
Drops characters
Table 6. Common Communications Problems
Interface
parallel - Interface cable defective
- Host/Network configuration
- Printer logic
- Terminating Resistors
serial - Host/Printer interface cable pinouts incompatible
- Host/Printer/Network configuration
- Set DTR and RTS both True
- Interface cable defective
- Printer logic
twinax - Interface cable defective
- Host-Printer definition
- Controller/Network configuration
- Printer logic
coax - Interface cable defective
- Controller/Network configuration
- Printer logic
Ethernet - Interface cable defective
- Host/Printer/Network configuration
- Printer logic
General Symptom List
Common Causes
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