HTP MODBUS/BACnet Installation guide

Brand: HTP

Model: MODBUS/BACnet

Type: Installation guide

MODBUS / BACnet Adapter Installation Instructions

Part # 7350P-636

For Use with BIC-928 Control Based EnduroTI and Elite Premier Boilers

BIC-926 Control Based Modcon, Modcon VWH, Pioneer, and Versa Flame Products Manufactured On or After July 1, 2011,

and BIC-926 Control Based Elite, Elite VWH, and Phoenix Water Heaters Manufactured On or After August 1, 2011

272 Duchaine Blvd. New Bedford, MA 02745 508-763-8071

lp-548 Rev. 5.1.17

STOP! Follow these instructions or warranty will be void!

The manufacturer reserves the right to make changes or updates without notice and will not be held liable for errors in literature.

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

NOTE: Contains additional information important to a procedure.

Foreword

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

For the Installer

The installer should be guided by the instructions furnished with the MODBUS/BACnet, local codes and utility company requirements.

Preference should be given to codes and requirements where they dier from the furnished instructions.

Additional publications which should guide the installer include:

1. The latest version of the National Electrical Code, NFPA No. 70.

In Canada, refer to Canadian Electrical Code C 22.1, from Canadian 2. Standards Association, 5060 Spectrum Way, Suite 100, Mississauga,

Ontario, Canada L4W 5N6.

Local, state, provincial, and national codes, laws, regulations, and ordinances.

This manual must only be used by a qualied heating installer

/ service technician. Read all instructions in this manual before

installing. Failure to comply could result in property damage or

improper appliance operation. Such damages or service calls to

correct operation ARE NOT covered by warranty.

The following dened terms are used throughout this manual to

bring attention to the presence of hazards of various risk levels

or to important product information.

CAUTION used without the safety alert symbol indicates a

potentially hazardous situation which, if not avoided, may

result in property damage.

Contents

Document History 2

Part 1 - General Information 2

A. What’s in the Box 2

B. Minimum System Requirements 2

C. Denitions 2

Part 2 - Installation 3

A. BMS Wiring Requirements 3

B. Jumper Setting 4

Part 3 - Communication Conguration 4

A. MODBUS/BACnet Enable 4

B. MODBUS Address 4

C. BACnet Address 5

D. Baud Rate 5

E. Parity and Stop Bits 6

Part 4 - MODBUS Registers and BACnet Objects 6

A. Primary Data Tables 6

B. Appliance Memory Map 6

C. Conguration Bits 9

Part 5 - Appliance Operation 9

A. Appliance Operation with MODBUS and BACnet

Communications 9

B. Example #1 - Enable / Disable CH and DHW Demand 10

C. Example #2 - Sending DHW Setpoint Via Direct Write Method 10

D. Example #3 - Sending Setpoint or Firing Rate from BMS 10

1. Sending Desired Setpoint from BMS to Appliance Via Simulated

0-10V Method 10

2. Send Firing Rate Command from BMS to Appliance 11

E. Example #4 - Hot Water Generation 12

F. Cascade 12

G. Temperature Conversions (MODBUS Only) 12

Part 6 - Troubleshooting 13

A. MODBUS/BACnet Board Diagnostics 13

B. Physical Layer 13

C. Communications 14

D. Error Codes 14

E. Appliance 0-7 Status Codes 14

F. Appliance 0 and Appliance 1 Blocking Codes 15

G. Appliance 0-7 Lockout Codes 15

Installation and Maintenance Notes 16

lp-548 Rev. 5.1.17

This adapter is capable of supporting either the MODBUS or BACnet protocols. The protocol selection is accomplished via dipswitch 10.

MODBUS and BACnet communication systems utilize a master-follower format where connected HTP appliances follow commands from a

building management system or other MODBUS or BACnet master device linked over an RS-485 serial connection.

Part 1 - General Information

One (1) MODBUS / BACnet Adapter

One (1) Bag of Mounting Hardware

One (1) Mounting Template

Ensure all components are included in the shipping crate. Move

components to the installation location.

Any claims for damage

or shortage in shipment must be led immediately against the

transportation company by the consignee.

CAUTION

If any system components are exposed to the following, do not operate until the aected components have been inspected by a qualied

serviceman.

1. FIRE

2. DAMAGE

3. SUBMERSION IN WATER

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

Document History

Revision Date Changes

1.22.16

1. Removed unsupported BACnet and MODBUS parameters from Memory Maps.

2. Added balance of Lockout and Blocking Codes to tables.

3. Consolidated MODBUS sections.

3.9.16

1. Consolidated BACnet and MODBUS sections.

2. Restructured document to better follow installation sequence.

3. Corrected temperature formula.

4. Added 16bit UINT columns to example tables.

11.15.16

1. Added training feedback for clarity.

2. Corrected RS485 polarity.

12.12.16 Added dipswitch diagram / matrix.

4.28.17 Revised to add water heater compatibility.

A. What’s in the Box

1. A MODBUS or BACnet master device, such as a Building

Management System (BMS) or computer with MODBUS or

BACnet master software, and an RS-485 serial port or USB port

with a converter to RS-485.

2. HTP MODBUS/BACnet adapter (this kit), and an HTP appliance/

water heater equipped with a BIC-926 control with rmware

revision MTSA-P110414 or greater. To determine whether your

BIC-926 based product is compatible with this adapter, refer to

Figure 1.

3. This MODBUS/BACnet adapter is also designed to work on the new BIC-928 control. There are no rmware limitations with this new

control.

4. Shielded twisted pair communication cable.

B. Minimum System Requirements

Abbreviation or Acronym Denition

ASCII American Standard Code for Information Interchange

BACnet

BACnet is a communications protocol for Building Management and Control networks. It is an ASHRAE, ANSI, and ISO

16484-5 standard protocol.

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 Input/Output

C. Denitions

Figure 1 - BIC-926 Controller Revision Label Location

Table 1 includes a list of denitions used throughout this manual.

lp-548 Rev. 5.1.17

Table 1 - Denitions

The MODBUS/BACnet adapter should be mounted to a solid surface. The adapter has two tabs with four mounting holes designed specically

for this purpose.

Part 2 - Installation

CAUTION

Use the mounting template and screws provided with the adapter. Damage to the MODBUS/BACnet adapter or appliance due to

installation with other mounting screws IS NOT covered by warranty.

When mounting the unit, keep in mind that the top cover must be removed to connect the RS-485 communication cable, and that the

appliance communication wire must reach the control inside the appliance.

The MODBUS/BACnet 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 input port.

In BIC-926 based appliances, the four pin connector from the adapter must be plugged into the white connector labeled X3 on the control.

In BIC-928 based appliances, the four pin connector from the adapter must be plugged into the black connector labeled X4 on the control.

NOTE: It is not recommended to install the MODBUS/BACnet adapter inside the appliance housing. Doing so may aect appliance operation

or damage the MODBUS/BACnet adapter.

A. BMS Wiring Requirements

RS-485 Communication Bus

• Maximum length: 4000 feet

• Cable specication: 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.

Figure 2 - Jumper Congurations in a MODBUS / BACnet Network

LSB Least Signicant Byte

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

MSB Most Signicant Byte

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

RS485 RS485 serial transmission of data standard

RTU Remote Terminal Unit

PG Industry Standard liquid-tight wiring entry connector

MB MODBUS

CAUTION

Damage to MODBUS/BACnet adapter or appliance due to improper installation IS NOT covered by warranty.

lp-548 Rev. 5.1.17

B. Jumper Setting

The appliance display handles most of the MODBUS/BACnet adapter conguration. There is one jumper on the MODBUS/BACnet 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/BACnet adapter is at the end of the RS-485 bus. Remove the jumper if the MODBUS/BACnet 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)

Part 3 - Communication Conguration

A. MODBUS/BACnet Enable

In order to enable either MODBUS or BACnet, push dipswitch 10 into the ON position to enable BAC, and the OFF position to enable

MODBUS. See the dipswitch matrix below for a detailed description.

Final Baud Rate Protocol

1 2 3 4 5 6 7 8 9 10

x4 BACNET

OFF OFF OFF OFF OFF OFF OFF OFF x1 MODBUS

Table 2 - Dipswitch Matrix

ENTER MENU CODE

925

LCD Display:

1. On the LCD display press and hold ENTER until you see the screen at the right.

2. Use the RIGHT arrow to select a character, then use the UP and DOWN arrows to select the

desired character value. RIGHT arrow over to the next character and repeat the selection. Once code 925 or 975 is on the screen

(Installer Menu code depends on the appliance - See appliance Installation Manual for details), press and hold ENTER on the display to

enter the Installer Menu.

3. Once in the Installer Menu, use the RIGHT or LEFT arrow to navigate to Parameter 37-MODBUS MODE. When at Parameter 37, press

ENTER, then use UP or DOWN to select the desired setting from Table 3.

4. Press ENTER to store the MODBUS Conguration. Press the RIGHT button to advance to Parameter 38 - Address.

LED Display:

1. On the LED display, press and hold TEMP and RESET simultaneously. Use the + and - arrows to show 925 on the display, then press and

hold TEMP to enter the installer menu.

2. Once in the Installer Menu, use the TEMP button to navigate to Parameter 37. When at Parameter 37, use + or - to select the desired

setting from Table 3.

3. Press the TEMP button to advance to Parameter 38 - Address.

Parameter 3 Character LED Display Setting LCD Text Display Setting Description

37 0 OFF MODBUS/BACnet “DISABLED” (factory default)

37 1 AUTOMATIC

MODBUS/BACnet “AUTO” (enables automatic detection of a PC

or Adapter)

37 2 ON MODBUS/BACnet “ON”

Table 3 - MODBUS MODE Settings

Please do not leave the Installer Menu after making this selection. Continue to congure the Address, Baud Rate, and Parity settings.

B. MODBUS Address

NOTE: MODBUS must be enabled on the appliance as outlined above for the following parameters to be viewed and changed.

lp-548 Rev. 5.1.17

C. BACnet Address

BACnet Device Instance

The unique BACnet Device instance number will consist of three (3) parts:

Base Number: 600000 Family:

BIC926 00000

BIC928 01000

The local address will be set by the MODBUS menu on the BIC. This address is the same as the address on the RS485 bus.

Example: A BIC928 with the RS485 address of 65 will have a device ID of 601065. A BIC926 with the RS485 address of 31 will have a

device ID of 600031.

NOTE: MODBUS must be enabled on the appliance as outlined above for the following parameters to be viewed and changed.

The BACnet address space is comprised of 256 addresses. These are dened as follows:

• Address 255 is a broadcast address. The master can send data to address 0 and all followers will process the data.

• Addresses 0 – 127 are free to be assigned to both Master and Follower BACnet nodes. Each address can be assigned to only one

BACnet device on the bus.

• Addresses 128 – 254 are valid only for Follower nodes.

ADDRESSING SUGGESTIONS*

• Each device must have a unique address.

• 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/BACnet adapter address in the appliance installer menu:

LCD Display:

1. When at Parameter 38, press ENTER, then use UP or DOWN to select the desired address.

2. Press ENTER to store the MODBUS Address.

3. Press the RIGHT button to advance to Parameter 39 – Baud Rate.

LED Display:

1. When at Parameter 38, press TEMP, then use + or - to select the desired address.

2. Press the TEMP button to advance to Parameter 39 – Baud Rate.

D. Baud Rate

The baud rate (communication speed) can be set on the control display to either 9600 or 19200 baud. All HTP appliances, as well as any

other device on the same bus and the MODBUS/BACnet master, must have the same baud rate setting. Select the highest baud rate that

oers the most reliable communication performance over the bus.

Some things that can aect 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.

LCD Display:

1. When at Parameter 39, press ENTER, then use UP or DOWN to select the desired setting from Table 4.

2. Press ENTER to store the Baud Rate.

3. Press the RIGHT button to advance to Parameter 40 – Parity.

LED Display:

1. When at Parameter 39, press TEMP, then use + or - to select the desired setting from Table 4.

2. Press the TEMP button to advance to Parameter 40 – Parity.

Parameter 3 Character LED Display Setting LCD Text Display Setting Description

39 0 9600 BAUD RATE = 9600 (factory default)

39 1 19200 BAUD RATE = 19200

Table 4 - Parameter 39 Settings

The MODBUS address space is comprised of 256 addresses. These are dened 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.

lp-548 Rev. 5.1.17

The nal (RS-485) baud rate is determined by this setting in conjunction with dipswitch 9 on the adapter. The following table shows all

possible nal baud rate selections.

Control Baud Rate Setting Dipswitch 9 Position Final RS-485 Baud Rate

9600 OFF 9600

19200 OFF 19200

9600 ON 36400 (9600 X 4)

19200 ON 76800 (19200 X 4)

Table 5 - Final Baud Rate Settings

E. Parity and Stop Bits

NOTE: This setting only applies to MODBUS operation. The BACnet protocol does not utilize parity for communication and this setting will

have no eect.

The parity/stop bits parameter of the MODBUS/BACnet adapter must be set to match the rest of the devices on the bus. Although it is

common to set serial devices to use no parity, setting the parity to even or odd may improve communications reliability on all connected

devices on the bus.

This parameter has 4 possible selections which should be sucient to establish communication with other devices. These selections are

outlined in Table 6.

LCD Display:

1. When at Parameter 40, press ENTER, then use UP or DOWN to select the desired setting from the table below.

2. Press ENTER to store the Parity.

3. Press and Hold the RESET button to store all parameters and exit the Installer Menu.

LED Display:

1. When at Parameter 40, press TEMP, then use + or - to select the desired setting from the table below.

2. Press and Hold the RESET button to store all parameters and exit the Installer Menu.

Parameter 3 Character LED Display Setting LCD Text Display Setting Description

40 0 1 ST No parity 1 stop bit (factory default)

40 1 2 ST No parity 2 stop bits

40 2 E PA Even parity 1 stop bit

40 3 O PA Odd parity 1 stop bit

Table 6 - Parameter 40 Settings

Part 4 - MODBUS Registers and BACnet Objects

A. Primary Data Tables

NOTE:

BOLD ITALICS

indicate objects that apply only to appliances equipped with BIC-928 operating systems.

Table Data Type Read / Write Description

Discrete Inputs Single bit Read only Data can be provided by an I/O system.

Coils Single bit Read / Write Data can be altered by an application program.

Input Registers 16-bit word Read only Data can be provided by an I/O system.

Holding Registers 16-bit word Read / Write Data can be altered by an application program.

Table 7 - Supplementary Information

B. Appliance Memory Map

MODBUS Heating Appliance Water Heater BACNET

Address Description Description Object Type Object Instance Unit Resolution

Discrete Inputs Discrete Inputs

00001 En / Room Th1 / Stg 1 N/A BV 0 1 = on, 0 = o 1

00005 Tank thermostat N/A BV 4 1 = on, 0 = o 1

10001 MHRL

High temp safety switch /

High ue temp switch

BI 0 1 = on, 0 = o 1

10002 Flow switch N/A BI 1 1 = on, 0 = o 1

10003 Gas Press. Switch N/A BI 2 1 = on, 0 = o 1

10005 Air Press Switch N/A BI 4 1 = on, 0 = o 1

10006 Blocked drain

Blocked vent pressure

switch

BI 5 1 = on, 0 = o 1

10007 ARHL

High temp safety switch /

High ue temp switch

BI 6 1 = on, 0 = o 1

lp-548 Rev. 5.1.17

MODBUS Heating Appliance Water Heater BACNET

Address Description Description Object Type Object Instance Unit Resolution

10008 Flame 1 Flame rectication probe BI 7 1 = on, 0 = o 1

10009 Enable / STG1 N/A BI 8 1 = on, 0 = o 1

10010 Tank th N/A BI 9 1 = on, 0 = o 1

10011 STG2 / APS N/A BI 10 1 = on, 0 = o 1

10033 Run-time cont. 1 Run-time cont. 1 BI 32 1 = on, 0 = o 1

10034

Alarm cont. 1

(EXCEPT Versa Hydro)

Alarm output BI 33 1 = on, 0 = o 1

10035 CH pump 1 N/A BI 34 1 = on, 0 = o 1

10036 DHW pump 1 N/A BI 35 1 = on, 0 = o 1

10038 Gas valve 1 Gas valve BI 37 1 = on, 0 = o 1

10039 Sys pump N/A BI 38 1 = on, 0 = o 1

10049

Boiler 1 Run

(same as 11118)

Run status BI 48 1 = on, 0 = o 1

10050

Boiler 2 Run

(same as 10023)

N/A BI 49 1 = on, 0 = o 1

10051 Boiler 3 Run N/A BI 50 1 = on, 0 = o 1

10052 Boiler 4 Run N/A BI 51 1 = on, 0 = o 1

10053 Boiler 5 Run N/A BI 52 1 = on, 0 = o 1

10054 Boiler 6 Run N/A BI 53 1 = on, 0 = o 1

10055 Boiler 7 Run N/A BI 54 1 = on, 0 = o 1

10056 Boiler 8 Run N/A BI 55 1 = on, 0 = o 1

10057

Lockout 1

(same as 10034)

Lockout Status BI 56 1 = on, 0 = o 1

10058

Lockout 2

(same as 10042)

N/A BI 57 1 = on, 0 = o 1

10059 Lockout 3 N/A BI 58 1 = on, 0 = o 1

10060 Lockout 4 N/A BI 59 1 = on, 0 = o 1

10061 Lockout 5 N/A BI 60 1 = on, 0 = o 1

10062 Lockout 6 N/A BI 61 1 = on, 0 = o 1

10063 Lockout 7 N/A BI 62 1 = on, 0 = o 1

10064 Lockout 8 N/A BI 63 1 = on, 0 = o 1

10065

Alarm relais ecs

(Versa Hydro ONLY)

BI 64 1 = on, 0 = o 1

Input Registers Input Registers

30001 Discrete Inputs 1-16 N/A AI 0 N/A 1

30002 Discrete Inputs 17-32 N/A AI 1 N/A 1

30003 Discrete Inputs 33-48 N/A AI 2 N/A 1

30004 *System / Cascade Setp. N/A AI 3 Deg F, O = 32 0.1

30005 System Pump 4 speed N/A AI 4 % 1

30006 Cascade Total Power N/A AI 5 % 1

30007 Cascade Current Power N/A AI 6 % 1

30008 *Outlet Setp. 1 N/A AI 7 Deg F, O = 32 0.1

30009 Outlet Temp. 1 Upper Temp Sensor AI 8 Deg F 0.1

30010 Inlet Temp. 1 Lower Temp Sensor AI 9 Deg F 0.1

30011 Flue Temp. 1 N/A AI 10 Deg F 0.1

30012 Firing Rate 1 Firing Rate 1 AI 11 % 0.1

30013 Boil. 1 Pump speed 5 N/A AI 12 % 1

30014 Boil. 1 Status Code Status Code 1 AI 13 N/A 1

30015 Boil. 1 Blocking Code Blocking Code 1 AI 14 N/A 1

30016 Boil. 1 Lockout Code Lockout Code 1 AI 15 N/A 1

30018 Outlet Temp 2 N/A AI 17 Deg F 0.1

lp-548 Rev. 5.1.17

MODBUS Heating Appliance Water Heater BACNET

Address Description Description Object Type Object Instance Unit Resolution

30021 Firing Rate 2 N/A AI 20 % 0.1

30022 Boil. 2 Pump 4 speed N/A AI 21 % 1

30023 Boil. 2 Status Code N/A AI 22 N/A 1

30024 Boil. 2 Blocking Code N/A AI 23 N/A 1

30025 Boil. 2 Lockout Code N/A AI 24 N/A 1

30026 Boiler Outlet 3 N/A AI 25 Deg F 0.1

30027 Boiler 3 Firing Rate N/A AI 26 % 1

30028 Boiler 3 Status N/A AI 27 N/A 1

30029 Boiler 3 Lockout N/A AI 28 N/A 1

30030 Boiler Outlet 4 N/A AI 29 Deg F 0.1

30031 Boiler 4 Firing Rate N/A AI 30 % 1

30032 Boiler 4 Status N/A AI 31 N/A 1

30033 Boiler 4 Lockout N/A AI 32 N/A 1

30034 Boiler Outlet 5 N/A AI 33 Deg F 0.1

30035 Boiler 5 Firing Rate N/A AI 34 % 1

30036 Boiler 5 Status N/A AI 35 N/A 1

30037 Boiler 5 Lockout N/A AI 36 N/A 1

30038 Boiler Outlet 6 N/A AI 37 Deg F 0.1

30039 Boiler 6 Firing Rate N/A AI 38 % 1

30040 Boiler 6 Status N/A AI 39 N/A 1

30041 Boiler 6 Lockout N/A AI 40 N/A 1

30042 Boiler Outlet 7 N/A AI 41 Deg F 0.1

30043 Boiler 7 Firing Rate N/A AI 42 % 1

30044 Boiler 7 Status N/A AI 43 N/A 1

30045 Boiler 7 Lockout N/A AI 44 N/A 1

30046 Boiler Outlet 8 N/A AI 45 Deg F 0.1

30047 Boiler 8 Firing Rate N/A AI 46 % 1

30048 Boiler 8 Status N/A AI 47 N/A 1

30049 Boiler 8 Lockout N/A AI 48 N/A 1

30050 Discrete Inputs 49 - 64 N/A AI 49 N/A 1

30051 NTC 6 temperature N/A AI 50 Deg F 0.1

30052 NTC 7 temperature N/A AI 51 Deg F 0.1

30053 NTC 9 temperature N/A AI 52 Deg F 0.1

30054 Vortex 1 ow N/A AI 53 LPM 0.1

30055 Vortex 1 temp N/A AI 54 Deg F 0.1

30056 Vortex 2 ow N/A AI 55 LPM 0.1

30057 Vortex 2 temp N/A AI 56 Deg F 0.1

30091 Total Faults

N/A

AI 90 1

30092 Total Last Faults

N/A

AI 91 1

30093 Run Hours CH AI 92 x5

30094 Run Hours DHW AI 93 x5

30095 Run Hours Cas CH N/A AI 94 x5

30096 Run Hours Cas DHW N/A AI 95 x5

30097 Power Hours AI 96 x5

30099 Start Counter AI 98 1

30100 Start Counter AI 99 1

Holding Registers

40001 Conguration Conguration AV 0

See Conguration

Bits Section

lp-548 Rev. 5.1.17

MODBUS Heating Appliance Water Heater BACNET

Address Description Description Object Type Object Instance Unit Resolution

40002 Coils Coils AV 1

See Conguration

Bits Section

40003 0-10 volt / rate / setp 0-10 volt / rate / set AV 2 V 0.1

40004 DHW setpoint DHW set AV 3 Deg F 0.1

40005 DHW temperatur DHW temp AV 4 Deg F 0.1

40006 Outdoor temp. Outdoor Sensor AV 5 Deg F 0.1

40007 Sys supply temp. N/A AV 6 Deg F 0.1

40008 Sys rtn temp. N/A AV 7 Deg F 0.1

40009 I4 for direct N/A AV 8 Deg F 0.1

40010 CH post purge N/A AV 9 Seconds 1

40011 DHW post purge N/A AV 10 Seconds 1

40012 Pump 4 Speed N/A AV 11 % 0.1

40014 Extra out ECS N/A AV 13 % 0.1

Table 8 - MODBUS and BACnet Memory Map - *Only Valid Valves During Heating Cycle

Address 40001/AV0 contains conguration bits sent from the BMS to the appliance. These bits tell the appliance to use its own internal

inputs, or inputs from the BMS. When a bit is set to 1, the appliance will ignore the corresponding value contained internally and expect the

BMS to write that value into the holding registers. The conguration bits are as follows:

C. Conguration Bits

Holding Register 40001 / AV0 Decimal Value HEX Value Selected Signal (Register) to Write to

0 = Taken from Control

1 = Taken from MODBUS

B0 (LSB) 1 01 Boiler enable (40002 / AV1) 0/1

B1 2 02 Tank enable (40002 / AV1) 0/1

B2 4 04

Rate command / 0-10V input / setpoint command

(40003 / AV2)

0/1

B3 8 08 DHW setpoint (40004 / AV3)* 0/1

B4 16 10 DHW temperature (40005 / AV4) 0/1

B5 32 20 Outdoor temperature (40006 / AV5) 0/1

B6 64 40 System supply temperature (40007 / AV6) 0/1

B7 128 80 System return temperature (40008 / AV7) 0/1

B8 256 100 I4 oset (40009 / AV8) 0/1

B9 512 200 CH post purge (40010 / AV9) 0/1

B10 1024 400 DHW post purge (40011 / AV10) 0/1

B11 2048 800 Pump 4 speed (40012 / AV11) 0/1

B12 4096 1000 Pump 5 speed (40013 / AV12) 0/1

B13 (MSB) 8192 2000 Extra 0-10V output (40014 / AV13) 0/1

Holding Register 40002 / AV1 Selected Signal (Register) to Write to)

Coil 01 b0 1 01 Room thermostat

Coil 05 b4 16 10 Tank thermostat

Table 9 - MODBUS Holding Registers

*The appliance will not respond to the internal DHW limit while the Tank Temperature AND Tank Enable is being written from MODBUS/

BACnet!

Part 5 - Appliance Operation

A. Appliance Operation with MODBUS and BACnet Communications

The appliance is equipped with a communication timer. Timeout is set for four minutes. The purpose of the timer is to ensure proper

temperature data is communicated to the appliance in a timely manner.

Additionally, the communication timer will provide fail safe operation should communication be lost. This timer will cause the appliance to

revert back to internal appliance controls should the communication be interrupted longer than the timer. The timer resets every time a

write command is received with updated temperatures or commands.

The master should update temperature registers at least once per minute, but no more than once per second.

Monitoring Only

Any appliance can be equipped with the MODBUS or BAC/net communication accessory and then be set up to operate with its own internal

controls. The master can then poll the MODBUS or BAC/net accessory for the read only variables. Refer to the following examples for

lp-548 Rev. 5.1.17

B. Example #1 - Enable / Disable CH and DHW Demand

In this conguration, the appliance is controlled by setting the setpoints locally on the appliance and providing an enable signal through

MODBUS or BAC/net communications.

All sensors and limiting devices (excluding the thermostat enable and tank thermostat enable signals, which will be sent to the appliance)

should be hardwired to the proper terminals in the appliance. The holding registers need to be set as follows:

Holding Registers Denition Decimal Value HEX Value Action

40001 / AV0 Conguration 3 0011 Set conguration to read 40002

40002 / AV1 Coils 1 0001 Enables CH Demand (00 00 disables demand) (boilers only)

40002 / AV1 Coils 16 0010 Enables DHW demand on appliance (00 00 disables demand)

40002 / AV1 Coils 17 0011 Enables both CH and DHW demand. DHW demand will have priority.

Table 10 - Example #1

D. Example #3 - Sending Setpoint or Firing Rate from BMS

In this conguration, the appliance setpoint is indirectly controlled by sending a 0 to 10v signal to it. All sensors and limiting devices (excluding

the 0 – 10 Vdc signal, which will be sent to the MODBUS/BACnet adapter) should be hardwired to the correct locations on the appliance.

For this command to function, congure the appliance according to the corresponding row in the table below.

1. Sending Desired Setpoint from BMS to Appliance Via Simulated 0-10V Method

Appliance Parameter I16 Parameter I17

Phoenix, Munchkin, MODCON rev2 and earlier 2 0

Elite, Elite Premier, EnduroTi 0-10 Volt Temperature

Table 11 - Send Desired Setpoint from BMS to Appliance

To send a desired CH setpoint on an appliance, or DHW setpoint on a water heater via 40003/AV2, the value (which equates to voltage

applied) must be determined through linear interpolation of programmable parameters on the BMS setup menu.

• Appliance temperature setpoint at low analog input = MIN BOILER TEMP (I12) in the 925 Installer Menu

• Appliance temperature setpoint at high analog input = CENTRAL HEAT in the 600 User Menu or PHOENIX in the User Menu

These variables set the temperature values corresponding to the minimum and maximum voltage settings of the 0 – 10 volt signal. The

defaults are as follows:

Parameter

Default Values Default

Deg C Deg F Voltages

Appliance temperature setpoint at low analog input 21 68 1.6

Appliance temperature setpoint at high analog input 82 180 10

Table 12 - 0-10 Volt Temperature Values for Setpoint

For example: Send a setpoint of 110

F. The formula to use for the interpolation is:

Voltage to be applied = (Desired setpoint – BMS temp at low analog input) (High voltage – low voltage) + Low voltage

(BMS temp at high analog input – BMS temp at low analog input)

From the default values:

Desired setpoint = 110

BMS temp at low analog input = 68

BMS temp at high analog input = 180

High voltage = 10

Low voltage = 1.6

[(110 - 68)(10-1.6)/(180 - 68)] + 1.6 = 4.75 volts

(4.75/10) x 100 = 47.5 48 = 30 Hexadecimal

A value of [00] [30] in hexadecimal would be written to holding register 40003/AV2 to issue a command for a 110

F setpoint.

NOTE: If your particular BMS supports DECIMAL inputs, then the desired voltage level can be sent directly. In the above example, you would

send 48 (4.8v) to 40003/AV2.

Holding Registers Denition Decimal Value HEX Value Action

40001 / AV0 Conguration 8 0010 Set conguration to read 40004/AV3

40004 / AV3 Coils Setpoint Setpoint Directly writes setpoint to water heater

C. Example #2 - Sending DHW Setpoint Via Direct Write Method

Table 13 - Example #2

conguring the writable Holding Registers.

*The appliance will not respond to the internal DHW limit while the Tank Setpoint is being written from MODBUS/BACnet!

lp-548 Rev. 5.1.17

Holding Registers Denition Decimal Value HEX Value Action

40001 / AV0 Conguration 4 04 Set conguration to read 40002

40003 / AV2 Setpoint 0-100 00-64 Enables CH Demand (00 00 disables demand)

Table 14 - Setting Holding Registers for Setpoint

Register 40003/AV2 needs to receive the setpoint command as follows: Acceptable range is 0 to 100. Value needs to be greater than 15 for

the appliance to re.

When the command is 16, the appliance will run with the setpoint controlled by the 925 menu parameter I12 (MIN BOILER TEMP). When

the command is 100 the appliance will run with the setpoint controlled by the 600 menu parameter CENTRAL HEAT on appliances or the

PHOENIX setting in the water heater user menu.

If the command value is anywhere between 16 and 100, the appliance will run at a setpoint proportional to the command sent between

minimum and maximum setpoints.

1.5V

10V

Figure 4 - Setpoint Curve

NOTE: To ensure proper operation, resend the conguration bits to holding register 40001 / AV0 prior to issuing a command.

In this conguration, the appliance is controlled by setting the modulation from 0 – 100%. Rate command will be 0 – 100% of the modulation

range. All sensors and limiting devices (excluding the 0 – 10 Vdc signal, which will be sent to the MODBUS/BACnet adapter) should be

hardwired to the correct locations on the appliance.

For this command to function, congure the appliance according to the corresponding row in the table below.

2. Send Firing Rate Command from BMS to Appliance

Appliance Parameter I16 Parameter I17

Phoenix, Munchkin, MODCON rev2 and earlier 2 2

Elite, Elite Premier, EnduroTi 0-10 Volt Fan Speed

Table 15 - Send Firing Rate from BMS to Appliance

The holding registers need to be set as follows:

Holding Registers Denition Decimal Value HEX Value Action

40001 / AV0 Conguration 4 04 Set conguration to read 40003

40003 / AV2 Rate Command 0-100 00-64 Sets Modulation %

Table 16 - Setting Holding Registers for Firing Rate

Register 40003/AV2 needs to receive the rate command as follows: Acceptable range is 0 to 100. Value needs to be greater than 15 for the

appliance to re.

When the command is 16, the appliance will run at minimum fan speed (ring rate). When the command is 100 the appliance will run at

max fan speed (ring rate) If the command value is anywhere between 16 and 100, the appliance will run at a fan speed proportional to the

command sent between minimum and maximum ring rates.

The holding registers need to be set as follows:

lp-548 Rev. 5.1.17

Figure 5 - Firing Rate Curve

NOTE: To ensure proper operation, resend the conguration bits to holding register 40001 / AV0 prior to issuing a command.

E. Example #4 - Hot Water Generation

Hot water generation can be accomplished using one of two methods when an appliance is connected to a BMS system, DHW with direct

control, and DHW with remote control.

DHW with Direct Control

This is the typical installation with a hot water generator in close proximity to the appliance with the tank thermostat, or tank temperature

sensor, wired to the terminal strip or Customer Connection Board of the appliance.

DHW with Remote Control

This installation may or may not have the hot water generator in close proximity to the appliance. Its sensors and thermostat values are only

available through the MODBUS communication bus.

Holding Registers Denition

BACnet

Decimal Value

MODBUS

Decimal Value

HEX Value Action

40001 / AV0 Conguration 26 26 001A Set conguration to read 40002, 4 and 5

40002 / AV1 Coils 16 16 0010 Enables Tank Tstat (00 00 disables appliance)

40004 / AV3 Tank setpoint 130.0 1300 82 Sets setpoint to 130.0F

40005 / AV4

Tank

temperature

150.5 1505 96 Passes tank temp from remote sensor (ex: 150.5F) to tank

Table 17 - Example #3

NOTE: To ensure proper operation, resend the conguration bits to holding register 40001/AV0 prior to issuing a command. For proper

hexadecimal conversion of rate percentage, please refer to the rate and temperature conversion section of this manual.

F. Cascade

In order to operate the appliance in cascade with MODBUS or BAC/net communications, congure the master appliance. Connect the

remaining appliances in the cascade through the normal cascade communications wiring. Cascade control can then be accomplished

automatically through the master appliance.

NOTE: With MODBUS or BAC/net communication connected only to the master appliance, only total cascade information can be seen

through the communications link. Information from the follower appliances is limited to follower appliance rate command, supply

temperature, fault code, and fault status.

If you want to see complete data from each follower, or use the master to control cascading of multiple appliances, each appliance will

need a MODBUS or BAC/net communication board. If this is implemented, you must remember that each appliance will present its data as

Appliance 1. You must then use the Appliance’s address to determine which follower you are accessing.

To ensure that the appliance can properly respond to a call for hot water generation, the following holding registers must be set in addition

to other commands:

*The appliance will not respond to the internal DHW limit while the Tank Temperature AND Tank Enable is being written from MODBUS/

BACnet!

G. Temperature Conversions (MODBUS Only)

The MODBUS adapter passes temperature data to the appliance in degrees Fahrenheit. Also, to accommodate decimal places, the decimal

value must be divided by 10.

In some BMS systems, the data sent over the MODBUS is passed as an unsigned 16-bit integer (16BIT UINT). This poses no problem unless

the data becomes negative, such as temperatures below zero. In this case, the compliment has to be calculated as follows:

lp-548 Rev. 5.1.17

Value 16BIT Unit BMS HEX BMS Signed Decimal BMS

80.5 F 0805 325 805

Table 18 - MODBUS Positive Outdoor Temperature Conversions

Sending negative outdoor temperature from remote sensor on BMS system to appliance (40006/AV5) = -25oF.

Data that needs to be transmitted is: -25 X 10 = -250. 65536-250=65286 OR -250 if supported.

Value 16BIT Unit BMS HEX BMS Signed Decimal BMS

-25 F 65286 FF06 -205

Table 19 - MODBUS Negative Outdoor Temperature Conversions

Positive outlet temperature from System sensor connected to BMS to appliance (40007/AV6) = 155oF. 155oF x 10 = 1550.

Value 16BIT Unit BMS HEX BMS Signed Decimal BMS

155 F 1550 60E 1550

Table 20 - MODBUS Positive Outlet Temperature Conversions

Part 6 - Troubleshooting

A. MODBUS/BACnet Board Diagnostics

Should you encounter problems communicating over MODBUS/BAC/net, the following items should be checked in this order.

1. Physical layer

2. Communications conguration and port settings

3. Error codes

4. Appliance status / blocking / lockout codes

The MODBUS/BACnet board is equipped with three LEDs for visual diagnostics: Two yellow and one green. These LEDs are located under

the MODBUS/BACnet cover. One yellow LED (D5) is used to indicate transmission of data. The other yellow LED (D6) is used to indicate

reception of data. The green LED (D7) shows internal faults. See Figure 6 for LED locations.

Internal Faults (Green LED):

Normal Operation = 1 second on, 1 second dim

Controller Fault = Continuously on

No Burner Control Communication = 0.5 seconds on, 1.5

seconds o

No MODBUS/BACnet Communication = 1.5 seconds on,

0.5 seconds o

Figure 6 - MODBUS/BACnet Diagnostic LEDs

B. Physical Layer

1. Adapter and Serial Port

a. Ensure adapter is plugged into the correct four pin

connector

i. It plugs into the WHITE connector on the BIC-

926 control.

ii. It plugs into the BLACK connector on the BIC-

928 control.

Example for WRITING negative temperature values to the appliance:

Temperature to be sent over MODBUS = -22oF.

First multiply by 10-22 X 10 = -220.

Calculate compliment 65536-220 = 65316.

Data to be sent is a decimal value of 65316.

Example for READING negative temperature values from the appliance:

To read the outdoor temperature from the appliance, do the opposite.

Read register 40006/AV5 and get 65316.

Since this value is greater than 32767, the temperature is negative. To calculate the negative value: 65536 – 65316 = 220,

then 220/10 = 22. 22 X -1 = -22oF.

NOTE: If your particular BMS supports DECIMAL outputs, then the desired temperature can be read and written directly.

More examples

Sending positive outdoor temperature from remote sensor on BMS system to appliance (40006/AV5) = 80.5oF

b. Conrm dipswitch 10 is in the correct position for the desired protocol.

c. Check for terminating resistors (120 ohms) at each end of the RS-485 bus only.

2. RS-485

a. Verify the correct MODBUS communication cable (twisted pair) is being used.

b. Check A, B terminal connections and polarity

c. Check for broken wires.

d. Check all wire lengths. Are any drops too long?

e. Check proper shield grounding.

lp-548 Rev. 5.1.17

C. Communications

1. Verify controller is congured for MODBUS (AUTO or ON)

2. Conrm dipswitch 9 is in the correct position for the desired nal baud rate.

3. Check baud rate (9600, 19200).

4. Check parity.

5. Check MODBUS/BACnet address.

6. Check port setting on master, gateway, and computers.

7. Check the status of the LEDs. Refer to Figure 6.

D. Error Codes

1. Check MODBUS communication error codes below.

2. Check Follower ID.

3. Check MODBUS command.

4. Check conguration bits for holding register 40001/AV0.

5. Check commands and data for holding registers 40002/AV1 through 40007/AV6.

NOTE: Use Status Codes, Blocking Codes and Lockout Codes to interpret remote appliance operating conditions.

E. Appliance 0-7 Status Codes

The appliance displays an appliance state code on the building screen to help aid in troubleshooting. The appliance state indicates what the

appliance is actually doing. This state should be compared to the command issued and what is expected. If the appliance state does not

agree with the command, check communication and conguration.

Status Codes

(Input Registers 30014, 30023, 30028, 30032, 30036, 30040, 30044, and 30048. Points AI13, 22, 26, 30, 34, 38, 42, and 46)

Number Denition

0 Standby

1 Blocking Sensor Short/Interrupt

2 Blocking Water Pressure

4 Blocking 24V Low

5 Blocking Temperature

6 DHW Function Internal

7 DHW Function Internal

8 DHW Indirect

9 DHW Direct

10 DHW Phoenix

11 DHW Spa

12 DHW

13 DHW

14 DHW

15 DHW

16 Service 1

17 Water Low 1

18 Water High 1

19 Water Low 2

20 Water High 2

21 CH On/O Thermostat

22 CH Zone Demand

23 CH Cascade Demand

24 CH Pool Demand

25 CH

26 CH

27 CH

28 CH

29 CH

30 CH

3. Network

Check that all components have power (appliance, MODBUS/BACnet adapter, gateway, BMS master).

lp-548 Rev. 5.1.17

Number Denition

31 CH None

32 DHW Post-Circulation Pump

33 CH Post-Circulation Pump

34 None

35 Service Pump

40 Lockout

51 Frost Protection Pump

52 Frost Protection Burner

60 Summer-Kick

61 Save EEPROM Blocking

96 Running

100 DHW Mode or Blocking for Cascade

101 Low Water Blocking

Table 21 - Appliance 0 - 7 Status Codes

F. Appliance 0 and Appliance 1 Blocking Codes

Blocking Codes

(Input Registers 30015 and 30024, AI14 and AI23)

Number Appliance Fault Denition

0 None

11 Water Pressure Low

12 S1 Temperature High

13 S2 Temperature High

14 Flue Temperature High

16 Regulation Temperature High

17 Not Enough Water Flow

21 Anti-Cycling CH

23 FLU Max Flue Pressure Switch / Max Start Cycles

25 Max Temperature Increase Limiting CH

26 24V too Low

30 Water Level Low 1

31 Water Level High 1

32 LEO Water Level Low 2

33 Water Level High 2

44 Common Flue Blocking

50 Burner Sensor Blocking

60 Blocking Flue Temperature Modulation

Table 22 - Appliance 0 and Appliance 1 Blocking Codes

G. Appliance 0-7 Lockout Codes

Lockout Codes

(Input Registers 30016, 30025, 30029, 30033, 30037, 30041, 30045, and 30049 - Points AI15, 24, 28, 32, 36, 40, and 44)

Number Fault Denition

0 None

177 AD Error

178 LWCO 1 Error

179 LWCO 2 Error

185 ECS6 Temperature Lockout

186 ECS7 Temperature Lockout

190 F05 S1 Maximum Temperature

191 F06 S2 Maximum Temperature

192 S1 Shorted

193 F02 S1 Interrupted

lp-548 Rev. 5.1.17

Number Denition

194 S2 Shorted

195 S2 Interrupted

196 Low Water Lockout

197 Flue Sensor Shorted

198 Flue Sensor Interrupted

199 Low Water Lockout 2

204 Parameters Damaged

205 Parameters Programmed

206 Error During Programming

207 Parameter EEPROM Failure

230 Fan LOW Error

231 Fan HIGH Error

232 No Flame During Running

233 F09 No Flame After Ignition

235 APS Stuck Closed

236 APS Stuck Open

237 F11 False Flame

239 F01 Safety Thermostat Open

240 F00 Flue Thermostat Open

241 External LWCO

243 Gas Pressure

243 Target Wall

244 Burner Sensor MAX Recycling

245 Burner Sensor Short

246 Burner Sensor Interrupt

Table 23 - Appliance 0-7 Lockout Codes

Installation and Maintenance Notes

HTP MODBUS/BACnet Installation guide

HTP MODBUS/BACnet Installation guide

HTP MODBUS/BACnet Installation guide

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