Rockwell Automation AADvance Controller Solutions Handbook - Manual (Page 35)

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Document: 553631
(ICSTT-RM447J_EN_P) Issue: 09:
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Modbus Master
The AADvance controller can be used as a Modbus master to one or more Modbus
slave devices. Slave devices can include programmable logic controllers, remote devices
(typically with little or no processing capability) and, more rarely, other functional
safety controllers (Trusted or AADvance).
The controller supports the Modbus RTU and Modbus TCP protocols, and a subset
of Modbus commands. You can use Modbus RTU with point-to-point and multi-drop
serial links, and Modbus TCP with Ethernet.
Note: The AADvance controller does not support the Modbus ASCII protocol.
You can set up an individual list of messages (commands) for each slave device.
Modbus read commands cause data to read from the slave device to the Modbus
master, while Modbus write commands cause data to be copied from the Modbus
master to the slave device. You can also define a sequence of broadcast write
commands, which a Modbus master can send to multiple Modbus RTU slaves without
requiring an acknowledgement. The AADvance controller can control and monitor
individual Modbus master objects and their slave links.
The Modbus master functionality has a safety integrity level of zero (SIL0) and should
only be used for non-safety applications.