### Settings of External Device

Define the communication settings for the External Device using the engineering software EcoStruxure Machine Expert – HVAC.

1. Start up the engineering software.

2. From the menu bar, click the [File] -> [New project].

3. Select M172 28-42 I/Os 596.11*1 in a pull-down menu for Target selection, and then click [OK] with any project name.
   *1 Numerical value added with the tail of model name is representing F/W version. It's could be different depending on your engineering tool version. And "M172 28-42 I/Os" is replaced with the controller you have as below.

   Controller Name | Target Name
   --- | ---
   M172O / M172P | M172 07-18 I/Os M172 28-42 I/Os
   M171P Flush | M171P Flush Mounting
   M171P | M171P Blind M171P Display

4. Connect USB Cable (A to mini-B) between your PC and the target controller.

5. From the menu bar, click the [On-line] -> [Setup communication…].

6. Activate [Modbus], then click [Properties] for configuring communication setting for Modbus.

7. Select USB port.

8. Navigate to a Commissioning tab.

9. Click [Connects To The Target] button.

10. From a tree menu, expand [M172 28-42 I/Os] -> [BIOS parameters] -> [All parameters], select [RS485-1 On Board] folder.

Setting | Folder
--- | ---
RS485-2 port on M172 | RS485-2 On Board
RS485 port on M171 | RS485 On Board
RS485 port on serial link module | RS485 Plugin Passive

11. Configure parameters are listed below.

    Name*1 | Setting Value | Notes
    --- | --- | ---
    Addr_RS485_OB1 | 1 | Modbus Port Number
    Proto_RS485_OB1 | 3 | 3=Modbus/RTU
    DataBit_RS485_OB1 | 8 | Data Bit
    StopBit_RS485_OB1 | 1 | Stop Bit
    Parity_RS485_OB1 | 2 | Parity Bit 0=None, 1=Odd, 2=Even
    Baud_RS485_OB1 | 2 | Baud-Rate 0=9600 1=19200 2=38400 3=57600 4=76800 5=115200

*1 Parameter Names are depending on selecting folder.

RS485-1 On Board | RS485-2 On Board | RS485 On Board | RS485 Plugin Passive
--- | --- | --- | ---
Addr_RS485_OB1 | Addr_RS485_OB | Addr_RS485_OB | Addr_RS485_OB
Proto_RS485_OB1 | Proto_RS485_OB | Proto_RS485_OB | Proto_RS485_OB
DataBit_RS485_OB1 | DataBit_RS485_OB | DataBit_RS485_OB | DataBit_RS485_OB
StopBit_RS485_OB1 | StopBit_RS485_OB | StopBit_RS485_OB | StopBit_RS485_OB
Parity_RS485_OB1 | Parity_RS485_OB | Parity_RS485_OB | Parity_RS485_OB
Baud_RS485_OB1 | Baud_RS485_OB | Baud_RS485_OB | Baud_RS485_OB

12. From the menu bar, click [Parameter] -> [Write all].

13. Reset the controller by power off/on.

NOTE

- To use the HVAC controller, select the [Use HVAC Controller] check box under [Equipment Settings] in the driver’s properties.

- When using a string variable, select ["BADC" from top address] from [String Mode] in the driver's properties. The character code that can be used is ASCII only.

- When “Use HVAC Controller” is checked, the following properties become disabled.
  - Addressing mode
  - IEC61131 Syntax
  - Mode
  - Communication Optimization
  - Preferred Frame Length
  - Length

- This driver uses variables exported from the EcoStruxure Machine Expert - HVAC. Import the exported variables by clicking [Import] from the toolbar on the variable editor of BLUE.

- Use an integer from 1 to 247 to enter the unit ID of the External Device.