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2019 Radiocrafts AS
MBUS User Manual (ver 2.01)
MBUS USER MANUAL
Access Number will be set automatically, depending on the incoming message. Before a transmission, the Access
Number can be set to a new value using the N-command. A reply to SND-IR and ACC-DMD use the incoming
Access Number for the reply.
7.5 Automatically reply with message from a mailbox
The Status byte will automatically be set to the incoming packet RSSI value. Normally a Standard Message is sent
as an answer to SND-IR and ACC-DMD using the same AN, but even if an answer is sent from the Mailbox, the AN
must be the same as the incoming message. For all other cases the Master will set a new AN. Using the single
level Auto-message handler (TLAM = 0) the Access Number is always incremented with no regard to the incoming
message.
7.6 Automatically reply with template from a mailbox
If the message in the mailbox has an Application Layer Address = 0, Access Number = 0 and Status = 0, the
message is called a
template
. When using a template, the blank fields will be added on-the-fly when responding to
the slave. This makes it possible to point at the same template message for many meters.
The RSSI of the last received packet will automatically be added in the Status byte by the module if set to zero.
The Access Number (AN) will automatically be increased for every new message transmission if set to zero in the
mailbox.
Note!
If the Template message requires encryption (as determined by the signature, and the Encryption
enable flag is set), the time to encrypt the message on-the-fly might violate the 2-3 ms response time in T-
mode. Templates with more than one block to be encrypted can only be used for S mode (up to 50 ms
response time). In this case the pre-encrypted mailbox message must be used.
7.7 Two-level auto-reply
Using the two level Auto-message handler (TLAM=1) the Master AN will not be incremented if the message is
repeated (because the last Master reply was not received by the Slave, the Master AN will be used again). For a
new message the Master AN is incremented automatically.
The RSSI of the last received packet will automatically be added in the Status byte by the module if set to zero.
7.8 Automatic Addressing
When the Master receives a message from a slave, this slave’s address will be used as the Application Layer
Address for the next transmission from the master when using the auto-message feature.
When messages are sent from the UART buffer, the Application Layer Address used is determined by the host.
Note!
The Link Layer Address (in the MAC header) is always the masters own address as stored in the
configuration memory. The Application Layer Address can be changed
by using the ‘T’ command (volatile
memory), or permanently changed using the ‘M’ command (non-volatile memory).
7.9 MBUS4: Key Challenge Function to support infinite number of installed slaves
The N2 timing includes a response time of 100 ms (fast) or 1100/2100 ms (slow) after the Slave message is
received. This timing is handled by the Master module. Also, a sleeping Slave will wake up and listen after this
response time.
