User guide

Redpine Signals, Inc. Proprietary and Confidential. Page 37
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Figure 2: Power Save Mode1 before Connection to an AP
After Wi-Fi Connection
In this state, the RS9110-N-11-2X module periodically wakes up to receive DTIM
(Delivery Traffic Indication Message) from the Access Point. Once it wakes up, it
sends “SLEEP\r\n”, in upper case ASCII ( 0x53 0x4C 0x45 0x45 0x50 0x0D
0x0A) message to host. If the host has data to be transmitted, it sends the data
packet instead of “ACK\r\n” to the module through the UART interface. Once
host finishes sending all packets, it can send “ACK\r\n” in upper case ASCII (
0x41 0x43 0x4B 0x0D 0x0A) to allow the module to go to sleep. If the AP sends
data to the module, all these packets will be given to the host before the module
checks “ACK\r\n” message to go to sleep. Hence, even if “ACK\r\n” has already
come from host, the module will not go to sleep if there are packets to be sent
to Host.
Sleep
Timer
Expired?
Yes
No
Module
wakes up
Go back to
sleep
Sends
“SLEEP\r\
n” to Host
“ACK\r\n”
sent from
Host?
Yes
No
Host should
make the
module scan and
join to an Access
Point