EN - 24
BMS communication protocol
Communication
interface
Transmission
mode
Remote signalling
register
(read-only)
RS485
3-pin connector, terminal block J13:
Terminal 1: A or +
Terminal
2:
B
or
–
Terminal
3:
for
a
shield
The line termination resistance can be configured with jumper W1:
Two lights provide information on the status of the transmission of date:
- D11: incoming light. Usually off; flashes when a message is received by
the board. If this light is continuously on, the bus is reversed. In this
case, swap terminals 1 and 2 on J9.
- D14: outgoing light. Usually off; lights up when the CPU sends a
message over the bus.
Serial, asynchronous, half duplex
-
1 start bit, 8 data bits, no parity bits, 1 stop bit.
- The bit rate can be set in parameter P104 to 4800 baud or
9600 baud.
Analogue value endcoding
Standard IEEE 32-bit format (2 registers)
Order of values:
- if P108 = 9600 or 4800
low order, high order
- if P108 = Jbus
high order, low order
Codes of functions used
1 or 2: read n bits
3 or 4: read multiple registers (16 bits)
5:
write one bit
6:
write register function
8:
read diagnostics counters
11:
read event counter
15:
write n bits
16:
write multiple registers (16 bits)
Note: Functions 15 and 16 are possible if parameter P103 is set to "Remote,
BMS…"
Error codes:
1 function
code
unknown
2
wrong address
3 data
error
Register 1: Board
type
Bits 0 to 7: Board type for AeroConnect = 32
Bits 8 to 15 0
Register 2: Operating
status
Bit 0:
On/off (1 = on => on and CA closed)
Bit 1:
Spray status 1 = on
Bit 2:
Free cooling status 1 = on
