Quectel EC200U Series, Примечание к применению

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LTE Standard Module Series
EC200U&EG915U_Series_PPP_Application_Note 10 / 28
3.2. Recommended Procedures for PPP Setting
Connect_Count
< 5
Power on the
module
AT+CPIN?
Query (U)SIM
card status
AT+CGREG?
Query PS network
1. Set APN by AT+CGDCONT
2. Start PPP dialing by ATD*99#
Return CONNECT
MCU got IP and
DNS
Data transmission
MCU sends
PPP
Terminate-
Request
packet
Connec+
Recommended Power-on/off:
For details of the recommended
power-on/off methods of each
applicable module, see their
Hardware Design documents
respectively.
Exit from the PPP dialing if (U)SIM
card is not ready in 20 s.
(U)SIM card is ready
Query (U)SIM Card Status:
AT+CPIN
. Reboot the module if it
fails to detect (U)SIM card in 20 s with
AT+CPIN? .
APN Configuration:
1. APN must be set by
AT+CGDCONT .
2. Use AT+CGACT? to check
whether the current context has been
activated when
AT+CGDCONT
returns error.
Y
Y
N
Packet Interaction:
1. Exit from the procedure of Packet
Interaction by
+++ .
2. The module will report NO
CARRIER when PPP connection is
terminated.
LCP Negotiation:
1. If UART is used, ensure the baud
rate between MCU and the module is
the same.
AUTH Negotiation:
1. Ensure the type of AUTH is one of
the following two: PAP(0xc023),
CHAP(0xc223).
IPCP Negotiation:
1. Check whether MCU has got legal
IP and DNS address.
2. Check whether the amount of DNS
MCU is equal to the amount
requested by MCU.
3. Terminate PPP connection if IPCP
negotiation between TA and TE is not
completed in 90 s, and then retry PPP
setup.
Exception Handling:
1. Check whether the PPP Terminate-
Request packet is right.
2. Reboot the module if the steps
above do not work.
Start timer when
IPCP negotiation
begins
Succeed to
negotiate IPCP in
90 s
Y
N
MCU receives
PPP Terminate-
Ack packet in 3 s
Send Count
< 5
Exception handling
Send Count++
LCP negotiation
AUTH negotiation
IPCP negotiation
Packet Interaction
OK
OK
OK
N
Y
Y
N
N
1. Synchronization between TE and TA.
2. Fix and save baud rate by AT+IPR=xxx&W . If
USB modem port is used, this could be ignored.
Network:
1. It indicates that the module has
registered on network when
AT+CREG? returns 1 or 5.
2. Reboot the module if it fails to
register on network in 60 s.
Exit from the PPP dialing if
the module fails to register
on network in 60s
AT+CREG?
Query network
status
Register on network in 60 s
PS Network:
1. It indicates that the module has
registered on PS when
AT+CGREG?
returns 1 or 5.
2. It is able to go to next step without
registering on PS in 60 s.
Figure 3: Flowchart of Recommended Procedures for PPP Setting