InHand InDTU324, User Manual

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Figure 4-11-7 Enabling SNTP time synchronization
4.11.7 Short Message Sending/Receiving
Each English short message to be sent can contain up to 160 English characters. A long message
is sent if there are more than 160 English characters. The long message is divided into several short
messages, each of which contains less than 160 English characters. Sending is based on the long
message protocol. When sending English short messages to the DTU, the user device encapsulates
the ASCII value of the English characters in the TLV of the short message content.
For example, the short message content to be sent is "hello0123456!".
Step 1: Encapsulate the destination phone number, short message content, and short message
format into an SMS command according to the IHDMP protocol. For example, "hello0123456!" and the
destination phone number are encapsulated into a hexadecimal instruction according to the IHDMP
protocol:
55AA55AA1300258180000B313538313836323330313081810001028182000D68656C6C6F3031323
334353621A25F. (For more information, see the IHDMP protocol documentation.)
Step 2: Download a serial port tool by using the browser, connect to serial port 1 of the InDTU, set
the sending/receiving format to HEX, and copy the compiled instruction to the serial port tool, as shown
in Figure 4-11-8. (UartAssist is used here.)