Serial interface
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isoLR275_D00127_00_M_XXEN/07.2018
6.3
BMS protocol
This protocol is an essential part of the Bender measuring device interface
(BMS bus protocol). Data transmission generally makes use of ASCII
characters.
Interface data are:
Baud rate:
9600 baud
Transmission:
1 start bit, 7 data bits, 1 parity bit, 1 stop bit
(1, 7, E, 1)
Parity:
even
Checksum:
Sum of all transmitted bytes = 0 (without CR and
LF)
The BMS bus protocol works according to the Master-Slave principle. That
means that one device represents the master while all other bus devices are
slaves. It is important that only one master is present in each network. All bus
devices are identified by a unique address. The master scans all other devices
on the bus cyclically, listens to their signals and then carries out specific com-
mands. Bus address 1 must be assigned to the master, thus to one of the
isoLR275 devices.
DI1
1
32
33
64
