Northern UTA220/UTA220k - Manual (Page 92)

12-16
UTA220/UTA220k
D-Channel X.25
X.3 PARAMETERS AND VALUES
Just as the AT commands control some of the operating
features of the TA, the X.3 parameters control the PAD’s
operating features. These parameters are user configurable and
remote configurable: the remote device can change the local
PAD parameters to designate how the PAD handles the data.
Most X.3 parameters govern how the data displays because the
data display depends on the type of local DTE or application.
Other X.3 parameters govern PAD functions such as data
forwarding (when to stop packeting the data received from the
local DTE device and transmit the packet), editing, flow
control, and service signal control.
Saving the X.3 Parameter Configuration
When the TA is first powered up, the X.3 parameters are set
to the default (factory) settings (Table 12-5). PAD parameters
can be modified using the set or set and read PAD commands.
The PAD must be in the PAD command mode before the set
or set and read commands can be executed. During a virtual
call, the remote device can change the X.3 parameter
configuration from the user's set configuration. To avoid the
problems this may cause, the PAD saves the current settings
of the X.3 parameters to RAM an X.25 virtual call is initiated.
When the virtual call is disconnected, the saved X.3 parameter
settings are restored. The PAD does not save the current X.3
parameter settings when the virtual call connection is
established by the remote DTE.
CLR RPE Remote DTE procedure error detected by the remote DTE/DCE
interface
CLR NP Called DTE address not assigned to any DTE
CLR DER Called number out of order or not responding
CLR DTE Remote DTE cleared the call
CLR RNA Called DTE not subscribed to reverse charging acceptance,
allowing the called DTE to accept the calling DTE’s request for
reverse charging (the reverse charge facility in the facility request
field of the call request packet)
Table 12-4: PAD Clear Service Signals (Continued)