Modbus Serial Line Configuration

Adding a Device on the Modbus Serial IOScanner

Introduction

This section describes how to add a device on the Modbus IOScanner.

Add a Device on the Modbus IOScanner

To add a device on the Modbus IOScanner, select the Generic Modbus Slave in the Hardware Catalog, drag it to the Devices tree, and drop it on the Modbus_IOScanner node of the Devices tree.

For more information on adding a device to your project, refer to:

• Using the Drag-and-drop Method

• Using the Contextual Menu or Plus Button

NOTE: The variable for the exchange is automatically created in the %IWx and %QWx of the Modbus Serial Master I/O Mapping tab.

Configure a Device Added on the Modbus IOScanner

To configure the device added on the Modbus IOScanner, proceed as follow:

Step	Action
1	In the Devices tree, double-click Generic Modbus Slave. Result: The configuration window is displayed.
2	Enter a Slave Address value for your device (choose a value from 1 to 247).
3	Choose a value for the Response Timeout (in ms).

Step

Action

In the Devices tree, double-click Generic Modbus Slave.

Result: The configuration window is displayed.

Enter a Slave Address value for your device (choose a value from 1 to 247).

Choose a value for the Response Timeout (in ms).

To configure the Modbus Channels, proceed as follow:

Step	Action
1	Click the Modbus Slave Channel tab:
2	Click the Add Channel button:
3	Configure an exchange: In the field Channel, you can add the following values: oChannel: Enter a name for your channel. oAccess Type: Choose the exchange type: Read or Write or Read/Write multiple registers (i.e. %MW). oTrigger: Choose the trigger of the exchange. It can be either CYCLIC with the period defined in Cycle Time (ms) field or started by a RISING EDGE on a boolean variable (this boolean variable is then created in the Modbus Master I/O Mapping tab). oComment: Add a comment about this channel. In the field READ Register (if your channel is Read or Read/Write one), you can configure the %MW to be read on the Modbus slave. Those will be mapped on %IW (see Modbus Master I/O Mapping tab): oOffset: Offset of the %MW to read. 0 means that the first object that will be read will be %MW0. oLength: Number of %MW to be read. For example, if 'Offset' = 2 and 'Length' = 3, the channel will read %MW2, %MW3 and %MW4. oError Handling: choose the behavior of the related %IW in case of loss of communication. In the fieldWRITE Register (if your channel is Write or Read/Write one), you can configure the %MW to be written to the Modbus slave. Those will be mapped on %QW (see Modbus Master I/O Mapping tab): oOffset: Offset of the %MW to write. 0 means that the first object that will be written will be %MW0. oLength: Number of %MW to be written. For example, if 'Offset' = 2 and 'Length' = 3, the channel will write %MW2, %MW3 and %MW4.
5	Click OK to validate the configuration of this channel. NOTE: You can also: oClick the Delete button to remove a channel. oClick the Edit button to change the parameters of a channel.

To configure your Modbus Initialization Value, proceed as follow:

Step	Action
1	Click the Modbus Slave Init tab:
2	Click New to create a new initialization value: The Initialization Value window contains the following parameters: oAccess Type: Choose the exchange type: Read or Write or Read/Write multiple registers (that is, %MW) . oRegister Offset: Register number of register to be initialized. oLength: Number of %MW to be read. For example, if 'Offset' = 2 and 'Length' = 3, the channel will read %MW2, %MW3 and %MW4. oInitialization Value: Value the registers are initialized with. oComment: Add a comment about this channel.
4	Click OK to create a new Initialization Value. NOTE: You can also: oClick Move up to change the position of a value in the list. oClick Delete to remove a value in the list. oClick Edit to change the parameters of a value.

Step

Action

Click the Modbus Slave Init tab:

Click New to create a new initialization value:

The Initialization Value window contains the following parameters:

oAccess Type: Choose the exchange type: Read or Write or Read/Write multiple registers (that is, %MW) .

oRegister Offset: Register number of register to be initialized.

oLength: Number of %MW to be read. For example, if 'Offset' = 2 and 'Length' = 3, the channel will read %MW2, %MW3 and %MW4.

oInitialization Value: Value the registers are initialized with.

oComment: Add a comment about this channel.

Click OK to create a new Initialization Value.

NOTE: You can also:

oClick Move up to change the position of a value in the list.

oClick Delete to remove a value in the list.

oClick Edit to change the parameters of a value.

To configure your Modbus Master I/O Mapping, proceed as follow:

Step	Action
1	Click the Modbus Master I/O Mapping tab:
2	Double-click in a cell of the Variable column to open a text field. Enter the name of a variable or click the browse button [...] and chose a variable with the Input Assistant.
3	For more information on I/O mapping, refer to EcoStruxure Machine Expert Programming Guide.

Step

Action

Click the Modbus Master I/O Mapping tab:

Double-click in a cell of the Variable column to open a text field.

Enter the name of a variable or click the browse button [...] and chose a variable with the Input Assistant.

For more information on I/O mapping, refer to EcoStruxure Machine Expert Programming Guide.

Access Types

This table describes the different access types available:

Function	Function Code	Availability
Read Coils	1	ModbusChannel
Read Discrete Inputs	2	ModbusChannel
Read Holding Registers (default setting for the channel configuration)	3	ModbusChannel
Read Input Registers	4	ModbusChannel
Write Single Coil	5	ModbusChannel Initialization Value
Write Single Register	6	ModbusChannel Initialization Value
Write Multiple Coils	15	ModbusChannel Initialization Value
Write Multiple Registers (default setting for the slave initialization)	16	ModbusChannel Initialization Value
Read/Write Multiple Registers	23	ModbusChannel