User`s guide

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Enable this parameter if this unit is to be the Master in an unbalanced link, or “Off” if the
unit is to be a secondary station.
Polling Response Time
The poll time in milliseconds (if the unit is the master in an unbalanced link).
Polling Stations Addresses
This parameter lists the station addresses on the data link as a comma-separated list of hex
values (e.g. “c1,d1” for station addresses 0xc1 & 0xd1). This parameter is only applicable in
SNA mode.
SAPs
This parameter contains a list of SAP values which correspond to the station addresses.
DSAPs(blank=default)
This is the Destination SAP value, if left blank the SAP value above is used.
Send Null XID (XID with no Data)
When this parameter is set to “On” a null XID SSP message will be sent when the unit has
just received or sent a REACH ACK SSP message.
Send XID with Data
This parameter is a hex string to define binary data and defines an XID SSP message that
would be sent in response to a XIDFRAME SSP message being received.
Tx Turn Around Time
This parameter specifies the time in milliseconds between receiving a frame from an
outstation and transmission back to the same station. If this parameter is set to “0” this is
disabled and the Digi can respond immediately. The minimum non-zero value is 10ms.
Mode
This parameter is used to define the mode in balanced links. In unbalanced links (like
SNA/SDLC) the mode is defined by being master or the station, but for balanced links (like
HDLC).
N400 counter
This is the standard LAPB retry counter. The default value is 3 and it should not normally be
necessary to change this.
RR Timer
This is a standard LAPB/LAPD “Receiver Ready” timer. The default value is 10,000ms (10
seconds) and it should not normally be necessary to change this.
T1 timer
This is a standard LAPB timer. The default value is 1000 milliseconds (1 second) and under
normal circumstances, it should not be necessary to change it.
T200 timer
This is the standard LAPB re-transmit timer. The default value is 1000 milliseconds (1
second) and under normal circumstances, it should not be necessary to change it.
Window Size
This parameter is used to set the X.25 window size. The value range is from 1 to 7 with the
default being 7.
Disconnect link if there has been no activity for x seconds
This parameter may be used to specify the length of time (in seconds) before the link is
disconnected if there has been no activity. If this parameter is zero or not specified, then
the inactivity timer is disabled. It is useful to set this to a short period of time (say 120
seconds) when an LAPB instance is being used over ISDN. This timer can be used as a