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AMATRONIC
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LECTRONIC
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CENTRIC User Guide, rel. 3.4
7.2.6.4
MODBUS (OPTIONAL FEATURE)
The ability to use a Modbus link with the
Centric
is an optional feature, available by special order. A
password may be required to use this feature. If you do not have the appropriate password, contact your
distributor or sales agent.
Two types of Modbus links can be defined between the Centric and another device on the network: a serial
link or a TCP/IP link. The two types of links are not mutually exclusive. In either case, with regards to
Modbus, the Centric is a slave device to the Modbus master located elsewhere on the Modbus
communication network. The Centric will respond to queries from the Modbus master.
The Centric’s Modbus interface is compatible with most Building Management Systems (BMSs), using the
register numbers shown in Table 4.
Note:
The registers in Table 4 can be addressed either as holding registers (for example, 4x0001) or as
input registers (for example, 3x0001).
7.2.6.4.1
D
EFINING A
TCP
M
ODBUS LINK
Enter a unit ID (the Centric’s ID on the Modbus network) and a TCP port number, as supplied by your
Modbus network administrator, and select the “Allow TCP Modbus” checkbox.
7.2.6.4.2
D
EFINING A SERIAL
M
ODBUS LINK
Choose a protocol (RTU or ASCII) and a baud rate, as recommended by your Modbus network
administrator, and select the “Allow serial Modbus” checkbox.
The Centric’s physical connection for serial Modbus is a D9 connector located in “connector group 2” and
labeled RS485. (See Figure 62 and Figure 64.)
Figure 29: Defining Modbus communication parameters
