Siemens DataNET Hub (DNH) User Manual page 84

Command Descriptions,
76 • • • • Command Summary
Continued
dn window
dn window num
dn polldelay
dn polldelay time
dn portdelay
Displays the transmit "window" for the
HDLC protocol used by DataNET. This is
the number of I-frames that a station may
send before it must receive an acknowl-
edgment from the receiving station.
Sets the transmit window used by all
ports on the hub. The parameter "num"
must be a number 1 through 7. The de-
fault window size is 7. The hub does not
store the window size parameter in non-
volatile memory, so non-default values
will be lost after a reset.
The "poll delay" parameter applies only
to ports 1-8 on a hub. It controls the time
a hub will wait between polls of any port.
As soon as a hub finishes an exchange
of messages on one port, it will normally
advance immediately to the next "con-
nected" port and begin the next ex-
change of messages. If "poll delay" is set
to a non-zero value, the hub will enforce
a delay before each new exchange be-
gins. The "poll delay" is given in millisec-
onds and defaults to zero (no delay).
Sets the poll delay to the value given, in
milliseconds. Actual times are rounded
down to the nearest ten milliseconds.
This parameter gives the delay, in milli-
seconds, that a hub will enforce between
message exchanges with a particular
slave device. That is, before initiating a
poll to a slave device, the hub will make
sure that at least this much time has
elapsed since the last poll to the same
device. This keeps a hub from consum-
ing all of the slave device's processing
time by continuously polling it at short
intervals. This parameter defaults to 50
milliseconds.
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