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- Create a "standard project" and select "CODESYS Control for Raspberry Pi SL" as the device.
- Define the target system via Network search.
- Insert an Ethernet adapter, a Modbus_TCP_Master and a Modbus_TCP_Slave in the device tree.
- Adapt the "PLC_PRG" as follows:
Requirements for the Modbus slave
- Create a "standard project" and select "CODESYS Control Win V3" as the device.
- Define the target system via Network search (see Modbus master).
- Insert an Ethernet adapter and a Modbus_TCP_Slave_Device in the device tree.
Setting on the Ethernet adapter (master and slave)
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| Note |
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If no target system is determined, an error message appears, "Gateway not configured" |
Setting on the Modbus_TCP_Slave (master)
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- Enter the IP address of the slave device (in this case the CODESYS Control Win V3)
- Issue a unique ID for the Modbus configuration
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Tab 'Channel'
- Create an input register (counter that is sent by the Modbus slave device) – cyclic update every 100 ms.
- Create an output register for writing your own counter.
=> 
> 
I/O mapping
- Assign input and output variables.
| Note |
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The setting of the option "Enabled 1" is necessary, since the variable "xExec" is not used in any task and writing would therefore not work. |
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Settings on the Modbus_TCP_Slave_Device (slave)
Tab 'General'
Activate monitoring of the communication
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Warning The unit ID must not be used for Modbus TCP!
This is only used for TCP/RTU gateways.Info The unit ID is only used for forwarding (gateway) to a Modbus Serial Bus.
For TCP/IP, the MODBUS-Server is addressed by means of the IP address. In this case, the MODBUS unit ID is not used (the value 0xFF has to be used).
For a serial connection, the Modbus devices are addressed with unit IDs from 1 to 247 (0 is used for broadcast addresses).
Tab 'I/O mapping'
- Assign input and output variables.
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Downloading and starting the projects
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- Load the application to the controller.
Slave
- Load the application to the controller
| Note |
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The value changes only after transmission has been triggered manually in the master. |
