Network Configuration; Network Considerations; Modbus Configuration; Disable The Chiller - Daikin MicroTech III Installation And Maintenance Manual

The following section describes how to configure the Modbus
communication module for BAS network integration. Follow
these instructions to set addressing parameters using the
MicroTech III chiller unit controller.

Network Considerations

Standard Modbus network rules apply. The network is a daisy-
chain of unit controllers including all slaves and the master.
The Modbus standard recommends that the network be
terminated on each end with the characteristic impedance of
the network of approximately 120 ohms. Follow the guidelines
stated in the Modbus specifications (www.Modbus.org).

Modbus Configuration

The Modbus communication module is configured using the
keypad/display on the unit controller. The Modbus network
address (ident number) and transmission (baud) rate must be
set using the unit controller keypad display.
NOTE: You must set the network address within the valid
range of 1-247 and also verify the baud rate before
the unit controller can properly communicate on
the Modbus network. These parameters are only
available when the communication module is correctly
attached to the controller.
Table 3 describes these and other network parameters used to
establish communication between the unit controller and the
BAS. The items shown in boldface are required for minimum

network configuration.

A preview of the configuration procedure is listed directly
below, followed by detailed instructions for each step.

1. Disable the chiller

2. Enter the password
3. Set the network address and baud rate - typically done
during initial configuration
4. Set other network parameters as required
5. Save changes and cycle power to the unit controller
6. Enable the chiller
Disable the Chiller
1. Set the Unit On/Off Switch to "Off" from inside the control
panel of the unit. See

Enter Password

2. If you have not already entered a password and are
on the Main Menu, turn the circular knob on the unit
controller (Figure 9) until Enter Password is highlighted
from the menu list (Figure
entered a password, skip to Step 4.
3. Select Enter Password by pressing down on the circular
knob.
www.DaikinApplied.com
(Table 3)
Figure 6 for switch location.
10). If you have already
NOTE: If you are not at the Main Menu and need to enter
a password, press the Back button from any other
menu screen until you reach the Main Menu and then
follow steps 1-3.
4. Enter Password 5321 and then press Enter.
5. Scroll down to View/Set Unit and press Enter.
Figure 9: Unit Controller Main Features
Back button
Figure 10: Modbus Setup Menu: Enter Password

Set the Network Address

1. Disable the chiller and enter a password if these two
steps have not been done already.
2. Scroll down to Modbus Setup and press Enter.
3. Scroll down to Address and press Enter
Change this parameter to the value specified by the BAS
network administrator.
4. Press Enter again to confirm selection.
5. Proceed to the next section and set the baud rate. If the
baud rate does not need to be changed, there are two
options:
a. Go to the Set Additional Network Parameters
section and modify any remaining items.
b. Go to the Save Changes and Cycle Power
to complete the configuration process.
9 IM 969-5 • MICROTECH III CHILLER UNIT CONTROLLER
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Circular knob
(press down for Enter)
(Figure 11).
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