15
Dura Communication protocol
15.1
Message Format
The interface board supports a data rate of 19200 bits per second.
Data shall be transmitted with no parity, one start bit, and one stop bit.
The basic message format is shown below:
ATTN
ADDR
CMD
LEN
IHCHK
DATA
IDCHK
The minimum message length is 7 bytes.
15.1.1
Attention (ATTN)
This byte identifies the start of a message. The following three values are defined:
ATTN
Description
0x07
Command
0x06
Acknowledge
0x15
Negative Acknowledge
A remote master initiates a command using the 0x07 attention code. The interface board will reply with an acknowledge
(ACK) code if the command was received successfully, or a negative acknowledge (NACK) if the command contained
errors.
Note that the interface board will acknowledge messages, even if it fails to execute the actions contained within.
NACKs are only issued when the message format is corrupted, e.g. invalid checksums.
15.1.2
Address (ADDR)
This byte is used to identify and address individual interface boards. In a multi-slave configuration, the master can
target each interface board individually, in which case the addressed interface board will reply with either an ACK or a
NACK.
The remote master can address all interface boards simultaneously using the broadcast address. In this case the interface
boards will not reply.
ADDR
Description
0x00:0xFE Individual address space
0xFF
Broadcast address
User Reference Manual – DuraPanel series
PN: 07353-000 Rev B Page 18
