IBM 6400 Maintenance Information Manual page 71

Operator Panel
Message
021 RECEIVE BUFFER
OVERRUN
VERIFY
CONFIGURATION
022 UNIT ADDRESS
NOT RECEIVED
CHECK PRINTER
ADDRESS
024 SERIAL LINE
PARITY ERROR
VERIFY
CONFIGURATION
Table 4. Message List
Explanation
The print buffer has
overflowed on a serial
interface. The printed
output may contain
random * (asterisk)
characters.
Poll timeout on the
twinax interface
indicating the unit
address is not
recognized by the
printer.
The printed output
may contain random
? (question mark)
characters.
Corrective Action
1. Make a configuration printout. Verify that
the printer matches the host serial
interface configuration settings for Data
Protocol, Baud Rate, Data Bits, Stop Bits,
Parity, Data Terminal Ready, and
Request to Send.
2. Set printer serial interface parameters to
match those of the host.
3. Send a print job to the printer. If the
message appears, go to
Communications Failures, page 131.
Have the system administrator make sure the
printer address is correct.
1. Make a configuration printout. Verify that
the printer matches host serial
configuration settings for Data Protocol,
Baud Rate, Data Bits, Stop Bits, Parity,
Data Terminal Ready, and Request to
Send. Set printer serial interface
parameters to match those of the host.
2. Send a print job to the printer. If the
message appears, replace the serial data
cable.
3. Send a print job to the printer. If the
message appears, go to
Communications Failures, page 131.
4. If the printer is in a twinax environment,
check the error log for 024 errors and
inspect the customer's cable hook-ups.
Connect all communications cables
correctly.
5. Send a print job to the printer. If the
message appears, replace the twinax
auto-termination cable ("T" connector).
6. Send a print job to the printer. If the
message appears, replace the coax/
twinax multi-platform interface. (Refer to
the Coax/Twinax Multi-Platform Interface
Feature Installation and Operation Guide ,
Form Number S246-0149.)
Message List
71