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6 Operation
6.1 Requirements for Successful Operation
The Modbus TCP Module must be controlled by a Modbus client (such as a PLC), which complies with the Modbus Protocol Specifi-
cation. For successful operation, the client must also support all functions and interfaces described in this manual.
6.2 Device Classification
The Modbus TCP Module is a Modbus server and must be managed by a Modbus client over Ethernet.
6.3 Configuration Requirements for PLC
The PLC must be configured to map registers within the communication card to addresses within the PLC.
The device must be configured directly in the PLC. No extra files are required.
6.4 Enabling Network Control
MCD 200
For the soft starter to accept the fieldbus commands, a link must be fitted across terminals A1–N2 on the soft starter.
MCD 500
Input links are required across terminals 17 and 25–18 if the soft starter is being operated in auto-on mode. In hand-on mode, links
are not required.
Control via the fieldbus communication network is always enabled in local control mode and can be enabled or disabled in remote
control mode (parameter 3-2 Comms in Remote). See the VLT® Soft Starter MCD 500 Operating Guide for parameter details.
6.5 Ensuring Safe and Successful Control
Data written to the device remains in its registers until the data is overwritten or the device is reinitialized. The Modbus TCP Module
will not transfer successive duplicate commands to the soft starter.
If the soft starter is started via fieldbus communications but stopped via the LCP or a remote input, an identical start command
cannot be used to restart the soft starter.
If the soft starter may also be controlled via the LCP or the remote inputs (as well as via fieldbus communications), a control
command should be immediately followed by a status query to confirm that the command has been actioned.
6.6 Feedback LEDs
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Operation
Modbus TCP Module
Installation Guide