Black Box PI750A, Руководство пользователя

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MULTIPORT SPOOLER VIII (4-, 8-, and 12-Port Models)
Either of the following can happen when a timeout
expires during such a delay:
a) When transmission resumes, the Multiport
Spooler VIII assumes it has a new job, rather than a
resumption of the old job. Therefore, any form feed,
header, or character string assigned to the input port
is unnecessarily executed. Or,
b) If a new job is sent to the same output port
from a different source before transmission resumes,
the Multiport Spooler VIII switches to the new job
before completing the old one, because it thinks the
old one is finished.
Because of these possibilities, you need to set the
timeout for an input port long enough to ensure that
transmitted jobs will not be ended prematurely, but
short enough to allow other users fair access to the
same peripheral. For software packages that transmit
without interruption (for example, word-processing
software), set a 6-second timeout for the input ports.
In cases when you expect transmission interruptions
caused by disk accessing or vector processing (for
example, plotting from AutoCAD), you need to set
a longer timeout (about 30 seconds).
A direct command is recognized if it occurs within
the first 256 characters of a new job. If more than
256 characters of the same job are sent to the
Multiport Spooler VIII, the timeout on the entry
port must expire before another command can
be recognized. In this case, the timeout is used
to indicate when the MPS-VIII should interpret
command character strings as actual commands
and execute them.
To automatically reset an input-port timeout to
zero before a subsequent command is sent, use the
UCTP program to enable the Break feature (see
Section 7.3.3
).