Bms Connections - Modbus - andrews MAXXflo EVO Lite Installation And Maintenance Manual

6 Installation

6.6.4 BMS connections - Modbus

Modbus - Is a BMS language protocol which BMS systems can interface
with, either directly or through a gateway. Parameter values can be read
and written directly to the water heater controller.
Install the modbus device according to the instructions (see section 6.6.2
for location illustration).
Modbus settings:
Tab. 30
Menu Parameter
Modbus 6651
Slave address
6652
Baud rate
6653
Parity
6654
Stop bit
BSB (Boiler System Bus) - Is the communication system of the water
heater, which is used to send and receive information from the other con-
trollers (if fi tted) and can be used by the optional Siemens OZW672 Web
Server, to provide access to the heater via the Internet or mobile phone
app. Please contact Andrews Water Heaters for further advice.
50
Settings
If connecting more than one device to the
Modbus network, each heater must have its
own unique slave address.
All devices in the Modbus network must
have the same rate of transmission. The
higher the transmission rate the shorter
the lines between the devices has to be
(doubling the baud rate halves the cable
lengths).
Recommended baud rate with a cable of
less than 500m length "19,200"
All devices in the Modbus network must
have the same parity.
Recommended setting "Even"
All devices in the Modbus network must
have the same number of stop bits (1 or 2).
If 2 stop bits are set, then parity must be set
to none.
Recommended setting is "1"
MAXXfl o EVO Lite