Rainbow Electronics MG260 - Manual (Page 241)

FLYFOT-MG260-MODULE
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- the length of data for the status packet is always equal to 1,
- whenever a status changes (except break), all the status bits are included,
- these bits are off by default (and therefore the bits DTR and RTS), so it is necessary to send
a status packet to the target at the beginning of the multiplexing to start the transmission,
1 These status bits contain the V24 control information :
- SA contains DTR (signal CT108 . from terminal to IWF) and DSR (signal CT107 . from terminal to IWF),
- SB contains RTS (signal CT105 . from terminal to IWF) and DCD (signal CT109 . from IWF to terminal),
- X contains CTS (signal CT106).
For more information, refer to GSM 07.02
Î 2 . READY packet : the packet indicates that the target is ready to receive data :
- no data are transmitted in this packet (so the length is null),
Î 3 . BUSY packet : the packet indicates that the target is busy and can not receive data :
- like the ready packet, no data are transmitted,
Î other values : currently, these values are not used (reserved for future enhancement).
The checksum is calculated like the AT command packet checksum (addition of all the transmitted
bytes including the header bytes).
Examples
19.7.1.1 AT command and its answer
When there is no encapsulation the AT command transmitted on the serial link is like this (in
ASCII and hexadecimal):
AT\r\n Ù 0x41 0x54 0x0D 0x0A
and the answer is like this :
\r\nOK\r\n Ù 0x0D 0x0A 0x4F 0x4B 0x0D 0x0A
With the encapsulation in the serial link, the packet transmitted is (in hexadecimal) :
0xAA 0x04 0xE8 0x41 0x54 0x0D 0x0A 0x42
and the answer is like this :
0xAA 0x06 0xE8 0x0D 0x0A 0x4F 0x4B 0x0D 0x0A 0x60
19.7.1.2 Initialisation and Data packet
When the Multiplexing Mode is activated (+WMUX=1), the product sends 2 Data packets
after the establishment of a DATA call (after the CONNECT xxxx message) : 1 READY Packet and 1
STATUS Packet. To set the different signals to the right value, it is necessary to send a STATUS
packet to the product.
Here are some examples of STATUS packets :
0xDD 0x01 0x08 0x40 0x26 Ù
bit RTS is on
to start a data call, all the bits should be on :
0xDD 0x01 0x08 0xC0 0xA6 (bits DTR and RTS are on