HTP 7350P-629 User Manual

MODBUS

NOTE TO CONSUMER: PLEASE KEEP ALL INSTRUCTIONS FOR FUTURE REFERENCE.

INSTALLATION

TROUBLESHOOTING

MOD BUS Models

7350P-629

FOR USE WITH MODCON, MODCON VWH, PIONEER, VERSA-FLAME

MANUFACTURED ON OR AFTER JULY 1, 2011

FOR USE WITH ELITE, ELITE VWH

MANUFACTURED ON OR AFTER AUGUST 1, 2011

NOTICE: HTP reserves the right to make product changes or updates without notice and will not be held liable for typographical errors in literature.

120 Braley Rd. P.O. Box 429 East Freetown, MA 02717-0429 www.htproducts.com LP-372 Rev. 6.14.13

The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or to important information concerning the product.

DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.

WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.

CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in property damage.

FOREWORD

This manual provides guidelines for the use and installation of the Modbus communication system with HTP appliances.

FOR THE INSTALLER

The installer should be guided by the instructions furnished with the Modbus, local codes and utility company requirements. Preference should be given to codes and requirements where they differ from the furnished instructions.

Additional publications which should guide the installer include: The latest version of the National Electrical Code, NFPA No. 70. In Canada, refer to Canadian Electrical Code C 22.1, from Canadian Standards Association, 5060 Spectrum Way, Suite 100,

Mississauga, Ontario, Canada L4W 5N6.

TABLE OF CONTENTS

PART 1 - GENERAL INFORMATION .......................................................................................................................................... 3

A. WHAT’S IN THE BOX ................................................................................................................................................................. 4

B. MINIMUM SYSTEM REQUIREMENTS ...................................................................................................................................... 4

C. DEFINITIONS ............................................................................................................................................................................. 4

PART 2 - INSTALLATION ........................................................................................................................................................... 5

A. WIRING REQUIREMENTS ........................................................................................................................................................ 5

B. JUMPER SETTING .................................................................................................................................................................... 6

PART 3 – COMMUNICATION CONFIGURATION (APPLIANCES WITH A 3 CHARACTER RED LED DISPLAY) .................. 7

A. MODBUS ENABLE ..................................................................................................................................................................... 7

B. MODBUS ADDRESS .................................................................................................................................................................. 7

C. BAUD RATE ............................................................................................................................................................................... 7

D. PARITY AND STOP BITS .......................................................................................................................................................... 8

PART 4 – COMMUNICATION CONFIGURATION (APPLIANCES WITH AN LCD TEXT DISPLAY) ......................................... 8

A. MODBUS ENABLE ..................................................................................................................................................................... 8

B. MODBUS ADDRESS .................................................................................................................................................................. 8

If any system component(s) is/are exposed to the following, do not operate until the affected component(s) has/have been inspected by a qualified serviceman.

1. FIRE

2. DAMAGE

3. SUBMERSION IN WATER

C. BAUD RATE ............................................................................................................................................................................... 9

D. PARITY AND STOP BITS .......................................................................................................................................................... 9

PART 5 – GENERAL MODBUS INFORMATION ........................................................................................................................ 9

A. DATA TRANSMISSION MODE .................................................................................................................................................. 9

B. MODBUS BOARD DIAGNOSTICS............................................................................................................................................. 9

C. MODBUS COMMUNICATION .................................................................................................................................................. 10

D. MODBUS FUNCTION SET ...................................................................................................................................................... 10

E. MODBUS EXCEPTION CODES .............................................................................................................................................. 11

PART 6 - REGISTER MAP ........................................................................................................................................................ 11

A. PRIMARY DATA TABLES ........................................................................................................................................................ 11

B. APPLIANCE MEMORY MAP .................................................................................................................................................... 11

C. BLOCKING CODES ................................................................................................................................................................. 13

D. LOCKOUT CODES .................................................................................................................................................................. 14

E. STATUS CODES ...................................................................................................................................................................... 14

F. CONFIGURATION BITS ........................................................................................................................................................... 14

PART 7 - APPLIANCE OPERATION......................................................................................................................................... 15

A. APPLIANCE OPERATION WITH MODBUS COMMUNICATIONS .......................................................................................... 15

B. EXAMPLE #1 ............................................................................................................................................................................ 15

C. EXAMPLE #2 ........................................................................................................................................................................... 15

1. SEND FIRING RATE COMMAND FROM MASTER .................................................................................................................... 15

2. SEND TEMPERATURE COMMAND FROM MASTER ................................................................................................................ 16

D. EXAMPLE #3 – HOT WATER GENERATION ......................................................................................................................... 16

E. CASCADE ................................................................................................................................................................................ 16

F. RATE AND TEMPERATURE CONVERSIONS ........................................................................................................................ 17

G. APPLIANCE STATUS CODES ................................................................................................................................................ 19

PART 8 - TROUBLESHOOTING ............................................................................................................................................... 19

A. PHYSICAL LAYER ................................................................................................................................................................... 19

B. COMMUNICATIONS ................................................................................................................................................................ 19

C. LED DIAGNOSTICS ................................................................................................................................................................. 19

D. MODBUS ERROR CODES ...................................................................................................................................................... 19

INSTALLATION AND MAINTENANCE NOTES .............................................................................................................................. 20

HTP CUSTOMER INSTALLATION RECORD FORM...................................................................................................................... 21

PART 1 - GENERAL INFORMATION

Modbus communication systems utilize a master-follower format where connected HTP appliances follow commands from a building management system or other Modbus master device linked over an RS-485 serial connection.

Any claims for damage or shortage in shipment must be filed immediately against the transportation company by the consignee.

ABBREVIATION OR ACRONYM

DEFINITION

ASCII

American Standard Code for Information Interchange

BAS

Building Automation System

Baud (Baud Rate)

Number of data bits transmitted per second (bps)

BMS

Building Management System

EMS

Energy Management System

FDX

Full-Duplex

HDX

Half-Duplex

Hex

Hexadecimal Number (0-9, A-F)

I/O Box

Input/Output

LSB

Least Significant Byte

A. WHAT’S IN THE BOX

1. One MODBUS Adapter

2. One bag of mounting hardware

3. One mounting template

B. MINIMUM SYSTEM REQUIREMENTS

1. A Modbus master device, such as a Building Automation System (BAS) or computer with Modbus master software, and an RS-485 serial port or USB port with a converter to RS-485.

2. HTP Modbus adapter (this kit), and an HTP appliance/water heater equipped with a control with firmware revision MTSA-P110414 or greater. To determine whether your product is compatible with this adapter, refer to Figure 1.

3. Shielded twisted pair communication cable.

Figure 1 – Controller Revision Label Location

C. DEFINITIONS

Table 1 is a list of definitions used throughout this manual.

Modbus

A serial, half-duplex transmission protocol developed by AEG Modicon

MSB

Most Significant Byte

RS232

RS232 serial, full-duplex (FDX) transmission of data standard

RS485

RS-485 serial transmission of data standard

RTU

Remote Terminal Unit

Industry Standard liquid-tight wiring entry connector

MODBUS

Use the mounting screws provided with the adapter. Damage to Modbus adapter or appliance due to installation with other mounting screws IS NOT covered by warranty.

Damage to Modbus adapter or appliance due to improper installation IS NOT covered by warranty.

Table 1 – Acronym definitions

PART 2 - INSTALLATION

The Modbus adapter should be mounted to a solid surface. The adapter has two tabs with four mounting holes designed specifically for this purpose.

When mounting the unit, keep in mind that the top cover must be removed to connect the Modbus communication cable, and that the appliance communication wire must reach the control inside the appliance.

The Modbus adapter can be mounted on the side of the appliance OR the wall next to the appliance, as long as care is taken to avoid components behind the mounting surface. The mounting location must be within 3 feet of the appliance controller in order to be plugged into the controller programming port.

NOTE: It is not recommended to install the Modbus adapter inside the appliance housing. Doing so may affect appliance operation or damage the Modbus adapter.

A. WIRING REQUIREMENTS

RS-485 Communication Bus

 Maximum length: 1000 feet  Cable specification: 24 AWG / A,B (twisted pair) and GND shielded, with characteristic impedance: 120 ohm  Maximum load: 32 units (32 nodes)

Wires will be passed through the PG connector on the side of the adapter, then connected to the three position connector marked “X5” on the circuit board inside the adapter. A label is provided inside the adapter to ensure proper connections of A, B, and GND. Two wires (MB IN and MB OUT) may be attached to each X5 screw.

See Figure 2 for an example wiring diagram.

BMS

APPLIANCE X

X5X5

REMOVE JUMPER

(J1) FROM THIS

ADAPTER ONLY!

MODBUS ADAPTER

APPLIANCE 1

Figure 2 – Jumper Configurations in a Modbus Network

B. JUMPER SETTING

The appliance display handles most of the Modbus adapter configuration. There is one jumper on the Modbus adapter. When this jumper is in place (factory default) it connects a termination resistor across the data lines of the RS-485 connection. Leave the jumper in if the Modbus adapter is at the end of the RS-485 bus. Remove the jumper if the Modbus adapter is one of many connections and not at the end of the bus. See Figures 2 and 3.

Figure 3 – Modbus Termination Jumper Location (Highlighted in Grey)

Parameter

Setting

Description

MODBUS “DISABLED” (factory default)

MODBUS “ON”

MODBUS “AUTO” (enables automatic detection of a PC or Adapter)

Parameter

Setting

Description

BAUD RATE = 9600 (factory default)

BAUD RATE = 19200

PART 3 – COMMUNICATION CONFIGURATION (APPLIANCES WITH A 3 CHARACTER RED LED DISPLAY)

A. MODBUS ENABLE

1. Press and hold ENTER and RESET simultaneously. Use the UP and DOWN arrows to show 925 on the display, then press and hold ENTER to enter the installer menu.

2. Once in the Installer Menu, use the ENTER button to navigate to Parameter 37. When at Parameter 37, use UP or DOWN select the desired setting from the table below:

Table 2 – Parameter 37 Settings

Please do not leave the Installer Menu after making this selection. Configure the Address, Baud Rate, and Parity settings described below.

B. MODBUS ADDRESS

NOTE: Modbus must be enabled on the appliance as outlined above for the following parameters to be viewed and changed. The Modbus address space is comprised of 256 addresses. These are defined as follows:

 Address 0 is a broadcast address. The master can send data to address 0 and all followers will process the data.  Addresses 1 – 247 are free to be assigned to Modbus devices on the bus. Each address can be assigned to only one Modbus

device on the bus.

 Addresses 248 – 256 are not available for use.

MODBUS ADDRESSING SUGGESTIONS*

 Each device must have a unique address.  It is not recommended to use 1 as an address, as this is often the default address for various other Modbus devices

that may be on the bus.

 In order to keep track of addresses for future maintenance purposes, record all device addresses in the Installation

and Maintenance Notes section included in this manual.

*SAVE THIS DOCUMENT IN A SECURE LOCATION FOR FUTURE REFERENCE.

To set the Modbus adapter address in the appliance installer menu: From the Installer Menu, press the ENTER key to advance to Parameter 38. Use the UP and DOWN arrows to set the desired address.

Press the RESET button to store the address. Press the DOWN button to advance to Parameter 39 - Baud Rate.

C. BAUD RATE

The baud rate (communication speed) can be set to either 9600 or 19200 baud. All HTP appliances, as well as any other device on the same bus and the Modbus master, must have the same baud rate setting. Select the highest baud rate that offers the most reliable communication performance over the bus.

Some things that can affect communications are:

 Long wire runs  Wire quality  A noisy electrical environment  The number of devices on the bus.

These conditions may require using a lower baud rate. Use the UP and DOWN buttons to select the desired setting from the table below:

Table 3 – Parameter 39 Settings Press RESET to store the baud rate. Press the DOWN button to advance to Parameter 40 - Parity and Stop Bits.

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