SARA-R42 - Application note
UBX-20050829 - R02
Local connectivity
Page 16 of 58
C1-Public
☞
It is not possible to have parallel activities on AT terminals when the multiplexer is activated
through the
+CMUX
AT command. The only allowed parallel activity is present when it is defined a
system architecture with a PPP dial-up on one port and AT commands on the other port.
☞
URCs are sent to all available AT interfaces when the multiplexer functionality is applied.
☞
The multiplexer protocol is not supported in the configurations having the AUX UART interface
enabled (for example,
+USIO: 1, +USIO: 4
).
5.4
Point-to-point protocol (PPP)
Data (PSD) calls are possible over both primary UART and auxiliary UART interfaces.
☞
If the double UART configuration is used, the full V24 modem lines are not supported. In this
configuration, entering in OLCM or disconnecting the PPP connection via DTR line de-assertion is
not possible.
☞
Issue the AT+CVHU=0 command to make ATH over Online Command Mode (OLCM) work,
according to 3GPP requirements. If the module has a DUN/PPP activated and is in OLCM, the
command deactivates the PPP and the associated PDP context (if possible).
Further information about PPP dial-up establishment can be found in the Internet applications
development guide application note
and in the EVK-R4 user guide
5.5
Generic guidelines
To properly configure local connectivity, the following steps shall be considered:
1.
Set the required connectivity variant at first usage, via the
+USIO
AT command.
2.
Configure the GPIOs based on the set variant (especially in reference to the RI line), via the
+UGPIOC
AT command.
3.
Configure the power saving control mode based on the set variant, via the
+UPSV
AT command.