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TERMINAL ELIMINATOR PLUS
To broadcast to the slave devices attached to
all
TEPs on a given layer is
easier, but only if no slave ports lower than that layer are occupied by slave
devices. For example, again assuming that you’re starting from a Concentrate-
mode connection to the first-layer Terminal Eliminator Plus, to broadcast to
the slave devices attached to all third-layer TEPs, send “BC[CR]BC[CR]
BC[CR]”. However, if there are slave devices attached to second-layer or first-
layer TEPs, the first broadcast data they will receive will be “BC[CR]” or
“BC[CR]BC[CR]” respectively. Don’t use this “global broadcast” command
string if not all of your slaves are on the same layer.
To properly exit Broadcast Only Mode when you’re finished with a
cascaded connection, the disconnect/abort-command character of the
second-layer units must have been changed previously to something other
than the command character used by the first-layer unit (see
Section 4.2.7
),
and the command character of the third-layer units must have changed to
something other than those used by either of the higher two layers. For
example, assuming
• the first-layer command character is “N,” the second-layer character is
“O,” and the third-layer character is “P,”
• you want to exit the conversation immediately, throwing away any master-
port data that might remain in the TEP’s buffers, and
• you want to end up talking to the first-layer unit in its standard
Concentrate mode,
then send the “abort” command string “PPPPPPPPOOOOOOOO
NNNNNNNN”.
Since the TEP doesn’t support anything like a selective Broadcast mode or
a one-to-many selective Conversation mode, there is no straightforward way to
simultaneously establish a broadcast to the slave devices attached to some but
not
all of the subsidiary TEPs on a given layer. To broadcast through only
some of the TEPs on a given layer—and this might occur frequently if some of
the TEPs on a given layer are occupied only by slaves and others are occupied
only by subsidiary TEPs—you must command the desired TEPs into Broadcast
Only Mode, broadcast to their slaves, then exit Broadcast Only Mode, one
TEP at a time.
