Xerox 6030 User Manual page 278

PLTXX can not dequeue
Status: Failed to delete a job from logical printer PLTXX on the print service side.
Action: Check by the lpq command whether the specified job has already changed
from the wait status in the queue to the processing status.
connection busy
Status: Failed to establish connection for data transfer.
Action: No action is necessary. The print service side accepts data transfer requests
for up to 10 sessions. This message is displayed if requests are received for
more than 10 sessions. Usually, resubmission is executed on the client side.
250 Chapter 6 Ethernet Print Service (for UNIX)