3060/X21
109001UA
P
ATTON
E
LECTRONICS
C
O
.
I
NSTALLATION
A
ND
O
PERATIONS
M
ANUAL
1-2
Operation
Anti-streaming
A typical problem often encountered is a
“STREAMING” remote terminal. The streaming
problem can tie up an entire circuit until the offending device has recovered or is powered
down. A streaming condition occurs when a Sub-Channel remains active, disrupting the
polling sequence. The3060/X21 (CTS MD-X.21/TCB) provides two user selectable modes of
controlling a streaming condition, an automatic anti-streaming Abort Timer with eight
selectable block lengths and a setting to disable anti-streaming for large data block transfers,
and a manual Operator Control mode (front panel push button switch).
Automatic Anti-Streaming - Automatic Anti-streaming will block the asserted control signal
from the Sub-Channel Port, releasing the 3060/X21 (CTS MD-X.21/TCB) to accept requests
from any other Sub-Channel that has not been locked out due to a streaming condition. When
a Sub-Channel is locked out for streaming, a visual indication, by Sub-Channel, is provided on
the front panel.
The Sub-Channel will no longer receive data or Indicate(I) from the Master
Port. Any data sent to the Master Port by the streaming device will be lost. Once a Sub-
Channel is locked out due to streaming, the Sub-Channel will remain locked out until the
attached device removes the streaming condition. If Indicate (I)
(for DTE) or Control (C) (for
DCE) is held active, I/C lead must become inactive, if continuous data transitions have
triggered the Anti-Stream logic, the transitions must stop before the 3060/X21 (CTS MD-X.21/
TCB) will clear the Anti-Stream logic to that Sub-Channel. Removing the Sub-Channel via the
front panel disable switch will not clear the Anti-stream logic for a Sub-Channel once it has
been activated.
Manual Anti-Stream - A streaming condition caused by one of the attached terminals can be
quickly corrected by the 3060/X21 (CTS MD-X.21/TCB) via the associated front panel locking
switches. A switch is provided for each Sub-Channel and permits the rapid removal of a
streaming terminal without having to disconnect any cables or power down the offending
terminal. Terminals may be selectively removed for self-test and maintenance without affecting
the remaining Sub-Channels. Once the streaming condition has been corrected, the front
panel switch is simply depressed to the locked (Enable) position (Green indicator ON) to
reestablish normal operation. Removing a Sub-Channel with the front panel switch will block
data from the Sub-Channel going to the Master Port but will not block data going from the
Master Port to the Sub-Channel as the Automatic Anti-Stream option did.