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NOTE: When a port is selected via the Master Port, the RTS
lines will be ignored until the Master Port sends the turn off code.
When the Master Port is selected by RTS, all preamble codes
will be ignored. The port combiner function is not available with
the Master Port configured as a DCE or in expansion mode.
A typical application would be to have RTS and CTS tied together
on the master port. When RTS on port A is asserted, CTS on port A
will be asserted when a connection is established. If a port is not
connected to the master port, then CTS on that port will remain low.
Therefore, a port can monitor the handshake line to determine if a
connection has been established.
Enhanced Timer Mode -- Timer Features
The 232XS5 has an enhanced mode, which offers special timer
features. The timer features can be used to prevent slave devices
from receiving preamble commands, inadvertent switching from
binary/graphic file transfers, and inactive slave devices from holding
control of the master port. The timer has two different modes: an
inactivity mode and an inadvertent switch mode. When in inactivity
mode, the 232XS5 will monitor the data lines. If there is no activity
for the specified time, the selected slave port will be disconnected
from the master port. When in inadvertent switch mode, the
232XS5 will ignore switching commands for the specified period of
time. After this time has expired, the selected slave port will be
disconnected from the master port.
The timer functions are enabled via a jumper setting and
through software commands. Jumper JP6-A must be OFF
(removed) for the 232XS5 to be in enhanced mode. The
software commands follow the same format as preamble codes
used for switching. There are two commands that must be sent to
the 232XS5 to set the timer functions: Set Timer Value and Set
Timer Mode. These commands require an additional byte for data.
The Set Timer Value command requires the third byte to be an
ASCII "T" character. The data byte (fourth byte) must be a value
between ASCII "0" and ASCII "9". A value of "0" is used to disable
the timer. The time set by the Set Timer Value command
determines the length of time the 232XS5 wll wait before
disconnecting an inactive port, or the length of time it will ignore
switching commands from the master. Refer to Table 7 for timer
values. For example, sending the following string to the 232XS5 will
set the timer value to 5 seconds (assuming programmable character
is the factory default of 2).
10
B&B Electronics -- PO Box 1040 -- Ottawa, IL 61350
PH (815) 433-5100 -- FAX (815) 433-5109
232XS53800 Manual
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