Page
30
of
60
©
2019 Radiocrafts AS
MBUS User Manual (ver 2.01)
MBUS USER MANUAL
7 Two-way communication
In T-mode the master must reply with a new message within 3 ms after a received message, if further
communication shall take place. To meet this timing requirement, the module has multiple built-in options. These
include:
•
One mailbox flag register. This is found in configuration memory.
To alter the MAILBOX flags you need to use the M-command
•
One Auto-message flag register for each NVM-registered slave (1-64 in MBUS3, 1-128 in MBUS4) or internal
RAM-registered slave (MBUS4 only)
Auto-
message flags are set by the ‘A’-command (or ‘a’-command for MBUS4 slaves 129-132), and can be read
back with the ‘O’-command (‘o’-command)
•
15 mailboxes, each 64 byte long. Mailboxes can be combined.
Mailboxes can be written to by the ‘W’-command and read back using the ‘R’-command.
The RC1xxx-MBUSx modules supports 4 types of two-way communication:
•
Automatically reply with a standard message
•
Automatically reply with a predefined message from mailbox
•
Automatically relpy with a template from mailbox
•
Two Level Auto Message for handling a sequence of commands
The options that come into play, and the different modes of two-way communication are discussed in the following
subchapters.
7.1 Mailbox register
The MAILBOX configuration register is used to set certain features of the Auto-message Generator:
7
6
5
4
3
2
1
0
RR
TLAM
ACSM
ACMB
MBSM
DFC
A
Where:
Acronym
Description
Default Value
RR
Reserved for future use
00
TLAM
Two Level Auto Message Enable
If TLAM is set, the master checks the slave
reply Access Number and use two level auto-
message handling. When the two level
message handler is used the auto clearing
flags should not be set (ACSM=0,
ACMB=0).The auto-message flags/mailbox
will be cleared as a part of the two level auto-
message handler after a correct response is
received from the Slave.
0
ACSM
Auto Clear Standard Message
If the ACSM or ACMB bit is set, the auto-message flag
will be automatically cleared after a transmission.
1
ACMB
Auto Clear Mailbox
If the ACSM or ACMB bit is set, the auto-message flag
will be automatically cleared after a transmission.
0
MBSM
MailBox Special Messages
0: Mailbox will respond to any message type (C-field).
1: Auto-message function will check incoming C-field
and only reply if message is SND-NR, RSP-UD or
ACK.
1