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The terminal adaptor connected to the higher-speed endpoint buffers the data and meters it toward
the network at the rate of the lower-speed endpoint. This terminal adaptor also controls the data flow
from the attached equipment using the Trans.flow control mechanism. If Trans.flow is off or if the
attached terminal does not support Flow Control, then you cannot transmit data faster than the rate of
the lower-speed endpoint. The lower-speed endpoint must not attempt to perform end-to-end flow
control on the higher-speed endpoint, because data may be lost. For example, typing Flow Control
characters (e. g., CtrlS or CtrlQ) may cause loss of data.
If the conditions in the above paragraph cannot be met, then Mode 3 is the recommended data
protocol.
When Match.speed is set to off, a Mode 2 call to another endpoint can only be achieved if the other
endpoint is running at the same speed.
Without Help
Min.timer (Minimum Delay Timer)
Configurations: Asynchronous DCE, Asynchronous DTE
Data Protocols: X.25, Mode 3
Turning on this option optimizes packet data transmission initiated from either a person typing or a
computer.
If characters received from the attached data equipment are separated in time by more than 10
milliseconds or one character time at 300 bps (roughly 30 milliseconds), then packets are transmitted to
the network without artificial delay. This is the case for a person typing.
If characters are received more closely spaced in time than as described above, characters are
assembled into packets. This may be the case of a computer answering a data base query or transferring
a file. In general, the size of the packet equals the number of characters received prior to a gap in the
reception or a full packet whichever is less. An exception to the above occurs when the first packet
transmitted after a gap may contain fewer characters (possibly only one character).
Without Help
Interaction with Forwarding and Idle.timer: The Forwarding option has precedence over Min.timer.
For example, if Forwarding is set to a value other than off, Min.timer is ignored. Similarly, if
Forwarding is set to off and Min.timer is set to on, Idle.timer is ignored.
Asynchronous DCE and Asynchronous DTE
Option Values For Match.speed
Front Panel
With Help
0
OFF
1
ON
Asynchronous DCE and Asynchronous DTE
Option Values For Min.timer
Front Panel
With Help
0
OFF
1
ON
CHAPTER 4: DEFINITIONS OF 7500 OPTIONS
CMD
Factory Value
Mode
DCE
DTE
off
X
on
X
CMD
Factory Value
Mode
DCE
DTE
off
on
X
X
63
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