Messaging between RockBLOCKs
Exchange messages between RockBLOCKs registered to the same account.
RockBLOCKs in the same Delivery Group can exchange messages in the same way that users exchange messages with HQ. The only difference is, that each message will require a specific prefix indicating that it needs to be forwarded to another RockBLOCK.
ASCII mode messaging
Here's the sample code to send an ASCII message to a RockBLOCK with serial number 1234.
/* Issue AT command */ AT\r /* Receive response */ OK\r /* Turn off Flow Control */ AT&K0\r /* Receive response */ OK\r /* Insert ASCII message into MO buffer */ AT+SBDWT=RB0001234Hello\r /* Receive response */ OK\r /* Initiate an Extended SBD Session */ AT+SBDIX\r
Use 7 bytes (7 characters)
Regardless of the unit's serial number, the transmitted serial number needs to be 7 bytes. Add the necessary 0's at the beginning of the serial number when entering it (ex. 0001234).
Binary mode messaging
Here's the sample code to send a binary message to a RockBLOCK with serial number 1234.
/* Issue AT command */ AT\r /* Receive response */ OK\r /* Turn off Flow Control */ AT&K0\r /* Receive response */ OK\r /* Define binary message length in MO buffer, adding 2 for the checksum, ex. 10+2=12 */ AT+SBDWB=[<SBD Message Length>+<2 Byte Checksum>]\r /* Receive response */ READY\r /* Stream Binary Message */ <Binary Message> /* Receive Response */ <Status>\r OK\r /* Execute Send/Receive */ AT+SBDIX\r
Binary Message Prerequisites
In the binary message that will be streamed, it is mandatory to include:
- The RB prefix ("5242" in Hex)
- The exact serial number of the unit (ex. if "1234" then "0004d2" in Hex)
- The message body (ex. if "Hello" then "48656c6c6f" in Hex)
0 - SBD message successfully written to the ISU.
1 - SBD message write timeout. An insufficient number of bytes were transferred to ISU during
the transfer period of 60 seconds.
2 - SBD message checksum sent from DTE does not match the checksum calculated at the ISU.
3 - SBD message size is not correct. The maximum mobile originated SBD message length is 340 bytes. The minimum mobile originated SBD message length is 1 byte.
AT commands in this chapter
Updated almost 3 years ago