Eru devices

You can create several connections and several devices for one application, in this way you can easily change the connection of any device or create a new one without modifying the addresses or device configuration.

Eru is designed to allows users to connect, manage, monitor, and control diverse automation devices and software applications through one intuitive user interface. To create devices:

1. Click Devices in the project tree.
2. On the Devices table, right click on the table and select Add.
3. Configure the parameters.

Devices parameters

• Name: Used to customize the device identification.
• ID: Unique ID in the Modbus network. Called Slave address too.
• Retries: Try to connect a limited times before go to the next connection.
• Addresses: Modbus doesn't support tag browsing, this means you can not view the tags in the tag table. You have to create Addresses manually.
• Zero based: The Modbus specification states that Modbus addresses are to be zero based. Meaning Modbus addresses start at 0 instead of 1. To read a value from Modbus address 1024, 1023 is sent to the device. When connecting to devices that do not adhere to zero based addressing, make sure this option is not selected. This will cause 1024 to be sent to the device to read Modbus address 1024.
• Connection: Select a connection to be used to link devices to the real world.

Device addresses

Per the Modbus protocol specification, the following four basic types of addresses can be read from a device:

• Holding Registers (read/write 16 bit words)
• Input Registers ( read only 16 bit words)
• Coils (read/write bits)
• Discrete Inputs (read only bits associated with device input points)

If you are new in Modbus specifications, download the following doc Modbus spec, you can easily learn how to use modbus in matters of minutes.