SIRETTA ZETA- P Series, Руководство по оборудованию

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43
ZETA-xxP Series
Hardware Manual
rev D
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Low Power Mode Receiving Data
In the ultra low power state a special provision must be catered for when data is
received from a connected socket to be output over the serial port.
In this mode it is necessary to run the serial port in the following state:
1. Enable hardware flow control with AT&K3
2. Enable low power mode by issuing AT+CFUN=5
3. Setup a socket connection and establish an active connection
4. Enter ultra low power state by de-asserting DTR control line
5. De-assert RTS line
6. Wait for specified timeout to check for incoming data
When the timeout has expired, to check for data over the connected socket follow
the procedure below:
1. Assert DTR line to disable low power state and activate full serial port
2. Assert RTS line to receive full buffered data over serial port and wait for all data to
be received
3. When all data has been received de-assert RTS line
4. De-assert DTR line to re-enter low power state and wait for the specified timeout
to receive further data
Low Power Incoming Data Process Cycle
Follow process flow below to receive incoming
data over the cellular network when running in
low power state where the timeout has expired
and data is ready to be received.
Check for data from the cellular network
using the active connection
>> Assert DTR
>> Assert RTS
< Receive incoming data >
>> De-assert RTS
>> De-assert DTR
Wait for timeout to check for incoming
data from the cellular network connection.
NOTE -
While there is no data pending reception
from the cellular network, the modem does meet
the published low power consumption figures.
However, if there is data pending from the cellular
network, then the modem power consumption rises
to approximately 5mA at 12V until the data transfer
process has completed and low power state is re-
entered.
The modem does not automatically enter the full
power state when there is pending cellular network
data, so the connected application is required to
periodically poll the cellular network. If there is pending
data from the cellular network, this will immediately
start to be received over the serial connection. Once
the data transfer is complete, the modem can be put
back into the low power state where it will meet the
published power consumption figures.
The shorter the check interval, the less time will
be potentially spent at the higher 5mA current
consumption. The longer the check interval the less
power will be used checking for received data from
the network. Choose this check interval to match the
requirements of your system.