# Changing the quantity of a data item of a Modbus RTU slave

The quantity defines the number of registers to be read or written in a request. Example: If the offset is 0 and the quantity is set to 5, registers 0, 1, 2, 3 and 4 will be read.

1. You must add a data item to the Modbus RTU slave.

1. Open the device view.
2. In the device tree, double-click the slave whose data item you want to edit.
3. Select the data item you want to change.
4. Double-click the text box Quantity.
5. In the text box, enter the desired quantity value.
6. Press Enter.