Installation and Maintenance Manual

MicroTech® III Chiller Unit Controller

Modbus® Communication Module

For: Pathfinder™ Chiller, Model AWS
For: Air-Cooled Scroll Compressor Chiller, Model AGZ-D

NOTICE: Use this manual to physically install the Modbus Communication Module into the MicroTech III chiller unit controller and connect the chiller unit controller to your network. Use the appropriate Engineering Data (ED), known as the Protocol Information document, to integrate the unit into your network. The Protocol Information document contains addressing details, protocol information, and a list of the data points available to the network. See the Reference Documents section of this manual for details. MicroTech III control integration literature is available from your local Daikin sales representative and www.DaikinApplied.com.

© 2013 Daikin Applied

General Information

This manual contains the information you need to install the Modbus® Communication Module on a MicroTech III Chiller Unit Controller, incorporate it into the Modbus network, and maintain it.

NOTICE: This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with this instruction manual, may cause interference to radio communications. It has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his or her own expense. Daikin disclaims any liability resulting from any interference or for the correction thereof.

Description

Description

The MicroTech III® Modbus Communication Module incorporates a MicroTech III Chiller Unit Controller into a Modbus local area network (LAN). The Modbus Communication Module is a printed circuit board with a plastic enclosure that connects to the left side of the D-Net™ Module as shown in Figure 1 or directly to the unit controller. The Modbus Communication Module provides access to the unit controller variables and parameters via Modbus.

Note: D-Net Performance Services is an optional feature that provides remote monitoring and diagnostic capability for certain models of Daikin chillers. Please refer to supporting literature, available on www.DaikinApplied.com, for additional details about D-Net.

Application

The Modbus Communication Module connects the unit controller to a building automation system (BAS) on a Modbus local area network. It is the interface for the exchange of Modbus objects between the network and the unit controller. Refer to the MicroTech III Chiller Unit Controller Operation Manual, available on www.DaikinApplied.com, for keypad details.

Component Data

Figure 1 shows the Modbus Communication Module, located on the far left-hand side of the image below. It is connected to the D-Net Module, which is mounted directly to the unit controller. Figure 2 shows the important features of the Modbus Communication Module.

Figure 1. Modbus Communication Module Attached to MicroTech III Chiller Unit Controller

[Textual description of Figure 1: An image showing the Daikin MicroTech III chiller unit controller with the Modbus Communication Module attached to its left side, alongside a D-Net module.]

Figure 2. Modbus Communication Module Major Components

[Textual description of Figure 2: An image of the Modbus Communication Module, highlighting key components. It shows two network connectors labeled 'Network Connector Channel 0' and 'Network Connector Channel 1 (Not Used)', along with a 'BUS LED' and a 'BSP LED'. Terminal blocks for '+ Ref' and '- Ref' are also visible.]

Light Emitting Diodes (LEDs)

The Modbus Communication Module has a BSP LED and a BUS LED to indicate communication activity and status of the Modbus Communication Module. These indicators are visible when the communication module is connected to the MicroTech III Chiller Unit Controller and the unit is powered on (see Figure 2).

BSP LED

The BSP LED indicates the communication state between the Modbus Communication Module and the MicroTech III Chiller Unit Controller. The table below describes the status of the BSP LED.

¹ In the event that this should occur, cycle power to the unit controller to attempt to clear the problem. Contact the Controls Customer Support Group at 866-462-7829 for additional assistance if necessary.

BUS LEDs

The BUS LED indicates the communication status between the Modbus Communication Module and the Modbus network. The table below describes the status of the BUS LED.

Modbus Network Connector

An RS-485 connector connects the Modbus Communication Module to the Modbus Network and has three pins: +, -, and Ref. The Modbus Communication Module has two RS-485 ports, but only the top connector (Channel 0) is used (see Figure 2).

Board-To-Board Connector

The board-to-board connector connects the MicroTech III Chiller Unit Controller to the Modbus Communication Module (see Figures 3, 4, and 5).

Figure 3. Modbus Communication Module and Knockout

[Textual description of Figure 3: An image showing the Modbus Communication Module with an area marked 'Knockout permanently removed' and a 'Board-to-board connector'. It also indicates that the 'Slot in module must line up with baffle in board-to-board connector'.]

Figure 4. Diagram of Board-to-Board Connector

[Textual description of Figure 4: A diagram illustrating the board-to-board connector. It shows two rows of pins, with labels indicating '3.5mm-Element' and '1.4mm-Element'. It also shows 'Baffle' elements.]

Figure 5. Modbus Communication Module with Board-to-Board Connector Inserted

[Textual description of Figure 5: An image of the Modbus Communication Module with the board-to-board connector inserted into its port.]

Installation

Contents of the Modbus Communication Module Kit

The following is the list of items included in the field-installed kit:

• The Modbus Communication Module
• Board-to-board connector
• Installation Manual (IM 969)

Installing a new Modbus Communication Module

Follow these steps to install a Modbus Communication Module on the unit controller. The Modbus Communication Module can be connected directly to the unit controller itself or to an existing module, if one is attached.

1. Set the Unit On/Off Switch to “Off” from inside the control panel of the unit. This must be done prior to installing a new communication module. Refer to Figure 3, IM 1122 (Pathfinder chiller) or OMM 1087 (AGZ-D chiller), available on www.DaikinApplied.com.
2. Remove power from the unit controller.
3. Remove the knockout on the far left end of the unit controller itself (or additional module, if present). See Figure 3. Note: To prevent damage to the unit controller, insert a small screwdriver or other tool to the tab on the bottom of the unit controller and pull the screwdriver away from the controller.
4. Remove the knockout on the right side of the Modbus Communication Module.
5. Insert the board-to-board connector into the Modbus Communication Module (see Figures 3 and 4). Note that it only fits one way and that the baffles must line up with corresponding slots in Modbus Communication Module and the unit controller (see Figure 4).
6. Insert the other end of the board-to-board connector to the far-left side of the unit controller or other device (i.e. module), if attached (see Figure 1).
7. Insert the network cable connector into the Modbus Communication Module (see Figure 2 for location of network connection port).
8. Power up the unit controller.
9. The unit controller automatically resets itself approximately 30 seconds after it is powered up. This reset is necessary so that the Modbus Communication Module is synchronized with the unit controller.

Note: There is a limit of three devices that can be attached to the left side of the unit controller.

Replacing an Existing Modbus Communication Module

Follow these steps to remove an existing Modbus Communication Module from the unit controller and replace it with a new Modbus Communication Module.

1. Set the Unit On/Off Switch to “Off” from inside the control panel of the unit. This must be done prior to replacing communication module. Refer to Figure 3, IM 1122 (Pathfinder chiller) or OMM 1087 (AGZ-D chiller), available on www.DaikinApplied.com.
2. Remove power from the unit controller.
3. Locate the Modbus Communication Module to the left of unit controller (see Figure 1).
4. Pull the network cable connector from the Modbus Communication Module.
5. Grasp the Modbus Communication Module and carefully pull it from unit controller (or from an adjacent module, if it is attached to one).
6. Install the new Modbus Communication Module (see steps 2-5 from previous section).
7. Insert the network cable connector into the Modbus Communication Module (see Figure 2 for location of network connection port).
8. Power up the unit controller.
9. The unit controller automatically resets itself approximately 30 seconds after it is powered up. This reset is necessary so that the Modbus Communication Module is synchronized with the unit controller.

Integration

Once the Modbus Communication Module has been properly installed on the unit controller, it is then possible to integrate the unit controller into a building automation system (BAS) via the Modbus network. The configuration process is described in the following section.

Connecting to the Network

Network Topology

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 (about 120 ohms). Follow the guidelines stated in the Modbus specifications (see Reference Documents section for details).

Configuring the Modbus Communication Module

The Modbus Communication Module can be configured using the keypad/display on the MicroTech III Chiller Unit Controller. The unit is ready to operate after you have verified and configured the default parameter values in the unit controller for your particular network. Refer to the appropriate MicroTech III Chiller Unit Controller Operation Manual for default values and keypad operating instructions. Refer to Protocol Document ED 15121, available on www.DaikinApplied.com, for descriptions of the available Modbus variables.

Modbus Addressing

The network address for a MicroTech III Chiller Unit Controller is set in the unit controller keypad display. The Modbus network address and data transmission rate (Baud Rate) are only available in the keypad/display when the Modbus Communication Module is correctly attached to the controller. You must set the network address (or ident number), within the valid range of 1-247 and also verify the baud rate before the unit controller can properly communicate on the Modbus network (see Table 1).

Note: Refer to the appropriate MicroTech III Chiller Unit Controller Operation Manual for details regarding the unit controller keypad/display.

Configuring the Modbus Communication Module using the Keypad/Display

1. If you have not already entered a password, select Enter Password from the Main Menu screen (i.e. turn the circular knob on the unit controller until the cursor is in the proper location) and press Enter (i.e. press down on the knob). See Figure 6.
   • 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 follow step 1. See Figure 6 for the location of the Back button.
   • If you have already entered a password, skip to step 3. See Figure 6 if you are not certain whether or not a password has been entered.
2. Enter Password: 5321.
3. Scroll down to View/Set Unit (i.e. turn the knob clockwise) and press Enter.
4. Scroll down to Modbus Setup and press Enter.

Note: The Modbus Setup menu only appears if a Modbus Communication Module installed correctly (see Installation section of this document for details). If the Modbus Communication Module is installed correctly and this menu still does not appear, cycle power to the unit controller and repeat the procedure above.

6. Modify the parameters as necessary (see Table 1 for a complete list).
7. Change "Apply Changes” from No to Yes.

Figure 6. MicroTech III Chiller Unit Controller Password Menu and Main Features

[Textual description of Figure 6: An image of the MicroTech III Chiller Unit Controller's interface. It shows a 'Main Menu' with options like 'Enter Password', 'Unit Status', 'Off: Unit Sw', and 'Active Setpt'. It highlights the 'Back button' and the 'Circular knob (press down to Enter value)'.]

Verifying the Modbus Data Transmission Rate

The options for baud rate (in bps) include: 9600, 19200, 38400, and 76800. The factory default baud rate is 38400 bps. Follow the steps below to change the baud rate for desired network speed.

1. If you have not already entered a password, select Enter Password from the Main Menu screen (i.e. turn the circular knob on the unit controller until the cursor is in the proper location) and press Enter (i.e. press down on the knob). See Figure 6.
   • 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 follow step 1. See Figure 6 for the location of the Back button.
   • If you have already entered a password, skip to step 3. See Figure 6 if you are not certain whether or not a password has been entered.
2. Enter Password: 5321.
3. Scroll down to View/Set Unit (i.e. turn the knob clockwise) and press Enter.
4. Scroll down to Modbus Setup and press Enter.
5. Verify the Baud Rate as required by the network and change if necessary.
6. Change "Apply Changes” from No to Yes.

Configurable Parameters

Table 1 defines the network parameters of the Modbus Communication Module that are available via the unit controller keypad/display. At a minimum, you must set the network address (ident number) and verify the correct baud rate before establishing network communication between the unit controller and the BAS. Change remaining parameters as required for your network.

Note: To save changes to these parameters, select "Apply Changes” under Modbus Setup. For additional information on using the keypad/display, refer to the appropriate MicroTech III Chiller Unit Controller Operation Manual.

¹Parameters that require configuration for proper network communication.

Note: If unit controller application software requires uploading in the field, the network configuration parameters revert to their default values. Please contact the Chiller Technical Response Center at -877-349-7782 for assistance with upgrading unit controller application software.

Service Information

Test Procedures

If you can control the unit from its keypad, but you are not able to communicate with unit via the network, follows these steps:

• Check the network wiring
• Check the network parameters and verify that they are correct and that there are no duplicate devices on the network
• Check communications

If the Modbus Communication Module still does not respond, contact the Controls Customer Support Group at 866-462-7829.

Parts List

Installation Kit

This document contains the most current product information as of this printing. For the most current product information, please go to www.DaikinApplied.com. All equipment is sold pursuant to Daikin Standard Terms and Conditions of Sale and Limited Product Warranty.

Daikin Applied
800.432.1342
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