This depends on the driver. Some drivers will allow you to configure the word order globally for the driver. This would be done from a Data Conversion button on the Device Settings window. In EBPro go to <i>Home > System Parameters > Device > Settings… > Data Conversion. The Modbus driver has options to swap byte, word or double word order for 64 bit registers:
In addition the Modbus driver has the 5x register type. This reads holding registers by swaps the word order. You can use this to reverse the word order on a particular address, without affecting the the whole driver.
For more information refer to the Controller Information Sheet for the driver you are using.