AH500 Module Manual COM port can be set to UD Link mode or Modbus mode via the right key of the mouse. (Select Modbus Mode when using the standard Modbus protocol; select UD Link mode when using RS485 user-defined format). In the two-mode switch, please note that the previous mode will be lost after being changed into the other one. Modbus mode setting Click Read or Write to enter the MODBUS read or MODBUS write setting interface in the following left-side box. Right click on the following right-side box to select “Add Item” to add bit and word item of Read and Write. The upper part is bit item of Read/Write and the lower part is word item of Read/Write. 11-42