Crest Audio 3.5 Instructions Manual

FB-MODB Rev A

MODBUS COMMUNICATION

INSTRUCTIONS

Crest Models: 1.5 - 3.5

 WARNING

This manual must only be used by a qualiﬁ ed heating installer / service technician. Read all instructions, including this manual, the Installation and Operation Manual, and the Service Manual, before installing. Perform steps in the order given. Failure to comply could result in severe personal injury, death, or substantial property damage.

Save this manual for future reference.

Contents

1. INTRODUCTION

Deﬁ nitions .................................................................... 2

Minimum System Requirements .................................. 2

2. CONFIGURATION

Addressing ................................................................... 3

Timing Speciﬁ cations ................................................... 4

Parity ............................................................................ 4

Data Transmission Mode ............................................. 4

ModBus Board Diagnostics ......................................... 4

Internal Faults ......................................................... 4

ModBus Function Set ............................................. 5

ModBus Exception Codes ........................................... 6

3. MEMORY MAP

Primary Data Tables ..................................................... 7

Crest Boiler Memory Map ............................................7-8

Input Registers ........................................................ 8

Holding Registers .................................................... 8

Conﬁ guration Bits ......................................................... 8

4. WIRING REQUIREMENTS

Physical Wiring ............................................................. 9

Typical Boiler System Wiring .................................. 12-13

5. UNIT OPERATION

Unit Operation with ModBus Communications ...... 14-17

6. TROUBLESHOOTING ........................................... 18-21

7. DIAGRAMS

Ladder Diagram ............................................................ 22

Wiring Diagram ............................................................ 23

Revision Notes ................................................... Back Cover

1 Introduction

The information contained in this manual provides general guidelines for the implementation of ModBus communication with the Lochinvar Crest boiler.

All ModBus networks are implemented utilizing a master-slave arrangement where all Crest boilers are slaves and the master is a building automation system capable of communicating over a RS-485 serial connection.

Deﬁ nitions

Abbreviation or Acronym Meaning

ASCII American Standard Code for Information Interchange BAS Building Automation System Baud (Baud Rate) Number of data bits transmitted per second (bps) EMS Energy Management System FDX Full-Duplex HDX Half-Duplex Hex Hexadecimal Number (0 - 9, A - F) I/O Box Input/Output (I/O) LSB Least Signiﬁ cant Byte

ModBus® A serial, half-duplex data transmission protocol developed by AEG Modicon MSB Most Signiﬁ cant Byte

RS232

RS485 A standard for serial transmission of data based on the RS-485 Standard

A standard for serial, full-duplex (FDX) transmission of data based on the RS232 Standard

RTU Remote Terminal Unit

Minimum System Requirements

• BAS system or computer with a serial or USB port with a converter to RS-485.

Shielded twisted pair communication cable.

ModBus Instructions

2 Conﬁ guration

The ModBus communication board is equipped with a set of ten dip switches that are used to set the board conﬁ guration (address, baud rate, and parity settings). The ﬁ rst eight are used to set the address of each board. The ninth is used to set the baud rate. The tenth is used to set the parity.

Figure 2-1_ModBus Communication Board

DIP SWITCHES

LED’S

Addressing

The ModBus addressing space is comprised of 256 different addresss.

• 0 is reserved for broadcast messages from the master device

• 1 - 247 are free to use for each unique device

• 248 - 255 are reserved

To set the ModBus address the dip switches can be set in either the 0 position or the 1 position. For switches set to the 1 position their value will be added together to determine the address.

For each switch set to the 1 position it has the following value:

Dip switch 1 = 1 Dip switch 2 = 2 Dip switch 3 = 4 Dip switch 4 = 8 Dip switch 5 = 16 Dip switch 6 = 32 Dip switch 7 = 64 Dip switch 8 = 128

Any dip switch set to 0 has a value equal to 0.

Example:

To set the address of the ModBus board to 50, dip switches 2, 5, and 6 have to be set to the 1 position. The address is determined by adding the values of all the dip switches together.

Address = Value of Dip switch 1 + Value of Dip switch 2 + Value of Dip switch 3 + Value of Dip switch 4 + Value of Dip switch 5 + Value of Dip switch 6 + Value of Dip switch 7 + Value of Dip switch 8

In this example:

Address = 0 + 2 + 0 + 0 + 16 + 32 + 0 + 0 = 50

2 Conﬁ guration

ModBus Instructions

Timing Speciﬁ cations

The baud rate for the ModBus board is selectable with Dip switch #9.

1 = 19200 bps 0 = 9600 bps

Each message is started by at least 3.5 character times of silence. The maximum delay between frames is 1.5 character times.

When the system temperature and/or tank temperature is provided by the BAS to the boiler, it is critical that the temperature be updated every few seconds. If the boiler does not receive updated temperatures within a timeout period (installer adjustable), the control will revert to using its own sensor inputs (if sensors are connected). The timeout is programmable by pressing the MAIN MENU>>SETUP>>MODBUS buttons. The timeout is adjustable between 5 and 120 seconds. The default timeout is 10 seconds.

When the BAS is not providing either of these temperatures, but is still controlling the boiler (such as providing a modulation command), the BAS must refresh these commands at least every 4 minutes. If the commands are not refreshed, the boiler will revert to operating based on its own inputs.

Parity

Parity is set by the position of Dip switch #10.

0 = No Parity 1 = Even Parity

If No Parity is selected there will be two stop bits, otherwise there will be one.

Data Transmission Mode

Many ModBus bus master devices can be conﬁ gured to transmit data in either ModBus RTU or ModBus ASCII modes. Since RTU messages can be formatted to use fewer data bits and are therefore more efﬁ cient, RTU has been chosen to be used with all Lochinvar ModBus communication. Please ensure that the master device is transmitting ModBus RTU.

ModBus Board Diagnostics

The ModBus board is equipped with three LED’s for visual diagnostics: Two yellow LED’s and one green. One yellow LED (D5) is used to indicate reception of data. The other yellow LED (D6) is used to indicate transmission of data. The green LED (D7) is used to show internal faults.

Internal Faults:

Normal Operation = 1 second bright, 1 second dim Controller Fault = Continuously on No Burner Control Communication = 0.5 seconds on, 1.5 seconds off No ModBus Communication = 1.5 seconds on, 0.5 seconds off

ModBus Communication

The ModBus communication commands and exception codes that are supported by the ModBus communication board can be found on pages 5 and 6 of this manual.

2 Conﬁ guration (continued)

ModBus Function Set

ModBus Instructions

Function Sub Function

HEX Description

Dec HEX Dec

1 01 Read Coil Status 2 02 Read Input Status 3 03 Read Holding Registers 4 04 Read Input Registers 5 05 Force Single Coil 6 06 Preset Single Register 7 07 Read Exception Status 8 08 0 00 Diagnostic - Return Query Data

1 01 Diagnostic - Restart Communication 2 02 Diagnostic - Return Diagnostic Register 4 04 Diagnostic - Force Listen Mode

10 0A

11 0B Diagnostic - Return Bus Message Count

Diagnostic - Clear Counters and Diagnostic Registers

12 0C Diagnostic - Bus Communication Error Count 13 0D Diagnostic - Bus Exception Error Count 14 0E Diagnostic - Return Slave Message Count 15 0F Diagnostic - Return Communication Error Count 16 10 Diagnostic - Return Slave NAK Count 17 11 Diagnostic - Return Slave Busy Count 18 12 Diagnostic - Return Bus Character Overrun Count

20 14 Diagnostic - Clear Overrun Counter and Flag 11 0B Get Communication Event Counter 12 0C Get Communication Event Log 15 0F Write Multiple Coils 16 10 Write Multiple Registers 17 11 Report Slave ID 23 17 Read / Write Multiple Registers

2 Conﬁ guration

ModBus Exception Codes

MODBUS Exception Codes

Code Name Meaning

The function code received in the query is not an allowable action for the server (or slave). This may be because the function code is only applicable to newer

01 ILLEGAL FUNCTION

02 ILLEGAL DATA ADDRESS

devices, and was not implemented in the unit selected. It could also indicate that the server (or slave) is in the wrong state to process a request of this type, for example because it is unconﬁ gured and is being asked to return register values.

The data address received in the query is not an allowable address for the server (or slave). More speciﬁ cally, the combination of reference number and transfer length is invalid. For a controller with 100 registers, the PDU addresses the ﬁ rst register as 0, and the last one as 99. If a request is submittted with a starting register address of 96 and a quantity of registers of 4, then this request will successfully operate (address-wise at least) on registers 96, 97, 98, 99. If a request is submitted with a starting register address of 96 and a quantity of registers of 5, then this request will fail with Exception Code 0x02 “Illegal Data Address” since it attempts to operate on registers 96, 97, 98, 99 and 100, and there is no register with address 100.

ModBus Instructions

03 ILLEGAL DATA VALUE

04 SLAVE DEVICE FAILURE

05 ACKNOWLEDGE

06 SLAVE DEVICE BUSY

08 MEMORY PARITY ERROR

A value contained in the query data ﬁ eld is not an allowable value for server (or slave). This indicates a fault in the structure of the remainder of a complex request, such as that the implied length is incorrect. It speciﬁ cally does NOT mean that a data item submitted for storage in a register has a value outside the expectation of the application program, since the MODBUS protocol is unaware of the signiﬁ cance of any particular value of any particular register.

An unrecoverable error occurred while the server (or slave) was attempting to perform the requested action.

Specialized use in conjunction with programming commands. The server (or slave) has accepted the request and is processing it, but a long duration of time will be required to do so. This response is returned to prevent a timeout error from occurring in the client (or master). The client (or master) can next issue a Poll Program Complete message to determine if processing is completed.

Specialized use in conjunction with programming commands. The server (or slave) is engaged in processing a long -- duration program command. The client (or master) should re-transmit the message later when the server (or slave) is free.

Specialized use in conjuction with function codes 20 and 21 and reference type 6, to indicate that the extended ﬁ le area failed to pass a consistency check. The server (or slave) attempted to read record ﬁ le, but detected a parity error in the memory. The client (or master) can retry the request, but service may be required on the server (or slave) device.

0A GATEWAY PATH UNAVAILABLE

GATEWAY TARGET DEVICE

FAILED TO RESPOND

Specialized use in conjunction with gateways, indicates that the gateway was unable to allocate an internal communication path from the input port to the output port for processing as the request. Usually means that the gateway is misconﬁ gured or overloaded.

Specialized use in conjunction with gateways, indicates that no response was obtained from the target device. Usually means that the device is not present on the network.

ModBus Instructions

3 Memory Map

Primary Data Tables

Table Data Type Read / Write

Discrete Inputs Single Bit Read Only Coils Single Bit Read / Write Input Registers 16-Bit Word Read Only Holding Registers 16 Bit Word Read / Write

Crest Boiler Memory Map

Coils

Address Description Default Unit Min. Max. Resolution

00001 Boiler Enable 0 1=ON / 0=OFF 0 1 1 00005 Tank Thermostat 0 1=ON / 0=OFF 0 1 1

Discrete Inputs

10001 Manual Reset High Limit 0 1=ON / 0=OFF 0 1 1 10002 Flow Switch 0 1=ON / 0=OFF 0 1 1 10003 Gas Pressure Switch 0 1=ON / 0=OFF 0 1 1 10004 Louver Proving Switch 0 1=ON / 0=OFF 0 1 1 10005 Blower Proving Switch 1 0 1=ON / 0=OFF 0 1 1 10006 Blocked Drain Switch 0 1=ON / 0=OFF 0 1 1

10008 Flame 1 0 1=ON / 0=OFF 0 1 1 10009 Enable 0 1=ON / 0=OFF 0 1 1 10010 Tank Thermostat 0 1=ON / 0=OFF 0 1 1 10011 Blocked Flue 0 1=ON / 0=OFF 0 1 1 10013 Blower Proving Switch 2 0 1=ON / 0=OFF 0 1 1 10021 Flue Damper Proving Switch 0 1=ON / 0=OFF 0 1 1 10023 Flame 2 0 1=ON / 0=OFF 0 1 1

10033 Run-time Contacts 0 1=ON / 0=OFF 0 1 1 10034 Alarm Contacts 0 1=ON / 0=OFF 0 1 1 10035 SH Pump 0 1=ON / 0=OFF 0 1 1 10036 DHW Pump 0 1=ON / 0=OFF 0 1 1 10038 Gas Valve 1 0 1=ON / 0=OFF 0 1 1 10039 System Pump 0 1=ON / 0=OFF 0 1 1

10044 Vent Damper Relay 0 1=ON / 0=OFF 0 1 1 10046 Gas Valve 2 0 1=ON / 0=OFF 0 1 1 10049 Blower #1 Power 0 1=ON / 0=OFF 0 1 1 10050 Blower #2 Power 0 1=ON / 0=OFF 0 1 1 10051 Spark Igniter 0 1=ON / 0=OFF 0 1 1

ModBus Instructions

3 Memory Map

Crest Boiler Memory Map

Input Registers

Address Description Default Unit Min. Max. Resolution

30001 Discrete Inputs 1 - 16 0 NA 0 65535 1 30002 Discrete Inputs 17 - 32 0 NA 0 65535 1 30003 Discrete Inputs 33 - 48 0 NA 0 65535 1 30004 System / Cascade Setpoint 0 Degrees Celsius 0 130 0,5 30005 System Pump Speed 0 % 0 100 1 30006 Cascade Total Power 0 % 100 800 1 30007 Cascade Current Power 0 % 0 800 1 30008 Outlet Setpoint 0 Degrees Celsius 0 130 0,5 30009 Outlet Temperature 0 Degrees Celsius 0 130 0,1 30010 Inlet Temperature 0 Degrees Celsius -20 130 0,1 30011 Flue Temperature 0 Degrees Celsius -20 130 0,1 30012 Firing Rate 0 % 0 100 1 30013 Boiler Pump Speed 0 % 0 100 1 30014 Boiler Status Code 0 NA 0 65535 1 30015 Boiler Blocking Code 0 NA 0 65535 1 30016 Boiler Lockout Code 0 NA 0 65535 1

Holding Registers

40001 Conﬁ guration 0 NA 0 65535 1 40002 Coils 0 NA 0 65535 1

40003 40004 Tank Setpoint 0 Degrees Celsius 0 87,5 0,5

40005 Tank Temperature 0 Degrees Celsius -20 130 0,1 40006 Outdoor Temperature 0 Degrees Celsius -40 60 0,1 40007 System Supply Temperature 0 Degrees Celsius -20 130 0,1 40008 System Return Temperature 0 Degrees Celsius -20 130 0,1

0-10 Volt Input / Rate Command / Setpoint Command

0 % 0 100 1

Conﬁ guration Bits

Address 40001 contains conﬁ guration bits sent from the BAS to the boiler. These bits tell the boiler to use its own internal inputs, or inputs from the BAS. When a bit is set to 1, the boiler will ignore the corresponding value contained internally, and expect the BAS to write that value into the Holding Registers. The conﬁ guration bits are as follows:

Bit 0 (LSB): Boiler Enable Bit 1: Tank Thermostat Bit 2: Rate Command / 10 - 10V Input / Setpoint Command Bit 3: Tank Setpoint

Bit 4: System Supply Temperature Bit 5: Outdoor Temperature Bit 6: Tank Temperature Bit 7: System Return Temperature Bit 8 - 15: Not Used (Default = 0)

ModBus Instructions

4 Wiring Requirements

Note that when the System Supply / System Return Temperature and/or the Tank Temperature are provided by the BAS, they need to be refreshed every few seconds. This is required in order to prevent unwanted ﬂ uctuations in these temperatures. If these values are not provided every few seconds (timeout is programmable), the boiler will revert to its own internal control. If neither of these temperatures is provided by the BAS, but any of the other control signals are being provided, the BAS will still need to refresh these inputs at least every 4 minutes.

Physical Wiring

RS-485 Communication Bus

• Maximum Length = 4000 feet

• Cable Speciﬁ cation = 24 AWG / A,B (twisted pair) and GND Shielded, with characteristic Impedance = 120 ohm

• Maximum Load = 32 units (32 nodes)

NOTE: Cable must be terminated with 120 ohm impedance matching resistor on each end.

Figure 4-1_Terminal Strip Connections

FROM PREVIOUS BOILER

TO NEXT BOILER

TANK SENSOR

SYSTEM SUPPLY SENSOR

0-10V INPUT

SYSTEM PUMP

SHIELD

ABBASHIELD

SHIELD

393837

OUTDOOR SENSOR

BMS

CASCADE

OUTDOOR

SYSTEM PUMP

SHIELDBA

343332

CONTACTS

ALARM

RUN TIME

CONTACTS

TANK

SYSTEM RETURN SENSOR

TANK

SENSOR

SYSTEM SUPPLY

SYSTEM RETURN

302928

272625

THERMOSTAT

PROVING

LOUVER

ENABLE

LOUVER

RELAY

BOILER PUMP

0-10V OUTPUT

OUT

RATE

BOILER PUMP

SHIELD

-++

201918

SWITCH 1

AUX

SWITCH 2

AUX

MODBUS

COMMUNICATION BUS

SHIELDAB

SHIELD

BUILDING

MANAGEMENT

SYSTEM

AUX

TANK

DEVICE

LOUVER

ENABLING

RELAY

SWITCH

LOUVER

PROVING

AUX

SWITCH 1

SWITCH 2

THERMOSTAT

4 Wiring Requirements

Figure 4-2_Control Inputs

DHW THERMOSTAT /

SENSOR

ENABLING DEVICE

CASCADE

LOUVER PROVING SWITCH

SYSTEM SENSOR -

SUPPLY

SYSTEM SENSOR -

RETURN

LOW VOLTAGE

CONNECTION

BOARD

ModBus Instructions

OUTDOOR SENSOR

SEQUENCER / BUILDING

MANAGMENT SYSTEM

AUX SWITCH 1 & 2

0-10 INPUT FROM

SYSTEM PUMP

INLET TEMPERATURE

SENSOR

OUTLET TEMPERATURE /

HI-LIMIT SENSOR

FLUE GAS SENSOR

INLET AIR SENSORS

AIR PRESSURE SWITCH

MANUAL RESET

HIGH LIMIT

FLAME SENSOR 1 & 2

BLOCKED DRAIN SWITCH

MODBUS

BOARD

SMART CONTROL

MODULE

GAS PRESSURE SWITCHES

LOW WATER CUTOFF

BLOWER PROVING

SWITCHES

VENT DAMPER

PROVING SWITCH

DISPLAY PANEL

PC INTERFACE

4 Wiring Requirements (continued)

Figure 4-3_Control Outputs

LOW VOLTAGE

CONNECTION

BOARD

LINE VOLTAGE

FIELD SUPPLIED CONTACTOR MUST

BE INSTALLED

TERMINAL

SUPPLY

120V

SYSTEM PUMP BOILER PUMP DHW PUMP

MAX. 1.5 AMPS PER CONNECTION

STRIP

ModBus Instructions

0-10V OUTPUT TO

BOILER PUMP

ALARM BELL

LOUVER RELAY

RUN TIME CONTACTS

BOILER RATE OUTPUT

SEQUENCER / BUILDING

MANAGMENT SYSTEM

SMART CONTROL

MODULE

BOILER PUMP

CONTACTOR

SYSTEM PUMP

CONTACTOR

HWG PUMP

CONTACTOR

IGNITOR

BLOWERS

GAS VALVES

VENT DAMPER

DISPLAY PANEL

PC INTERFACE

4 Wiring Requirements

Modbus RS485 Port on Gateway or Building System

Figure 4-4_Control Location

MODBUS COMMUNICATION BOARD (MTR01)

CONTROLLER

ModBus Instructions

Typical Boiler System Wiring

Physical Configuration: Cascade without Individual Monitoring

Modbus RS485 Communication Bus

Cascade Daisy Chain Connection

4 Wiring Requirements (continued)

Physical Configuration: Cascade with individual Monitoring

Modbus RS485 Port on Gateway or Building System

Modbus RS485 Communication Bus

ModBus Instructions

Cascade Daisy Chain Connection

Physical Configuration: Direct Control

Modbus RS485 Port on Gateway or Building System

Modbus RS485 Communication Bus

ModBus Instructions

5 Unit Operation

Unit Operation with ModBus Communications

To control a Crest boiler through a Building Management System communicating through ModBus, the Crest Demand Conﬁ guration must be set to one of three options. These conﬁ gurations allow different control points for a variety of applications. The conﬁ guration can be set by selecting Main Menu>>Setup>>BMS.

The Crest boiler is equipped with a ModBus communication timer. This timer is programmable from 0 - 120 seconds. The timer can be programmed from the ModBus Setup Menu by selecting Main Menu>>Setup>>ModBus. The purpose of the timer is to ensure proper temperature data is communicated to the boiler in a timely manner. Additionally, it will provide for fail safe operation should ModBus communication be lost. This timer will cause the unit to revert back to internal unit controls should the ModBus communication be interrupted longer than the ModBus timer. The timer is reset every time a ModBus write command is received with updated temperatures or commands. It is the recommendation of Lochinvar that this timer be set to the shortest value possible.

When controlling a Crest boiler through a Building Automation System (BAS), it is very important to ensure that the correct conﬁ guration bits are sent to holding register 40001, and that the correct data and enable signals are sent to holding registers 40002 - 40007, per the demand conﬁ guration.

Demand Conﬁ guration: ENABLE = ACTIVE; BMS = INACTIVE

In this conﬁ guration the unit is controlled by setting the setpoints locally on the boiler and providing an enable signal through ModBus communications.

All sensors and limiting devices should be hardwired to the terminal strip on the back of the unit excluding the enable signal. This signal will be sent to the unit via ModBus.

The holding registers will need to be set as follows:

Holding Registers Deﬁ nition Bit Value (HEX) Action

40001 Conﬁ guration 00 01 Set Conﬁ guration to read 40002

40002 Coils 00 01 Enables unit (00 00 disables unit)

NOTE: To ensure proper operation re-send the conﬁ guration bits to holding register 40001 prior to issuing a command.

ModBus Instructions

5 Unit Operation (continued)

Demand Conﬁ guration: ENABLE = ACTIVE; BMS = ACTIVE

In this conﬁ guration the unit is controlled by providing an enable signal. The setpoint command will be determined by the parameters in the control and a rate command through ModBus communications.

The rate command will be 0 - 100% of modulation.

All sensors and limiting devices should be hardwired to the terminal strip on the back of the unit excluding the enable and 0-10V BMS signal. These signals will be sent to the unit via ModBus.

The holding registers will need to be set as follows:

Holding Registers Deﬁ nition Bit Value (HEX) Action

40001 Conﬁ guration 00 05 Set Conﬁ guration to read 40002 & 3

40002 Coils 00 01 Enables unit (00 00 disables unit)

40003 Rate Command 00 ## Sets Modulation % or Setpoint

NOTE: To ensure proper operation re-send the conﬁ guration bits to holding register 40001 prior to issuing a command.

For proper hexadecimal conversion of rate percentage, please refer to the Rate and Temperature Conversion section on page 17 of this manual.

Demand Conﬁ guration: ENABLE = INACTIVE; BMS = ACTIVE

In this conﬁ guration the unit is controlled by setting the modulation setpoint from 0 - 100%, or the setpoint. The setpoint command will be determined by the parameters in the control.

Rate command will be 0 - 100% of the modulation range.

All sensors and limiting devices should be hardwired to the terminal strip on the back of the unit excluding the 0 - 10Vdc signal. This signal will be sent to the unit via ModBus.

The holding registers will need to be set as follows:

Holding Registers Deﬁ nition Bit Value (HEX) Action

40001 Conﬁ guration 00 04 Set Conﬁ guration to read 40003

40003 Rate Command 00 00 Sets Modulation % or Setpoint

NOTE: To ensure proper operation re-send the conﬁ guration bits to holding register 40001 prior to issuing a command.

For proper hexadecimal conversion of rate percentage, please refer to the Rate and Temperature Conversion section on page 17 of this manual.

Hot Water Generation

Hot water generation can be accomplished with one of two methods when a Crest boiler is connected to a BAS 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 boiler with the tank thermostat, or tank temperature sensor, wired to the terminal strip of the unit.

ModBus Instructions

5 Unit Operation

DHW with remote control:

This installation may or may not have the hot water generator in close proximity to the boiler. Its sensors and thermostat values are only available through the ModBus communication bus.

To ensure that the Crest boiler can properly respond to a call for hot water generation the following holding registers must be set in addition to other commands:

Holding Registers Deﬁ nition Bit Value (HEX) Action

40001 Conﬁ guration 00 4A Set Conﬁ guration to read 40002, 4 & 5

40002 Coils 00 08 Enables Tank Tstat (00 00 disables unit)

40004 Tank Setpoint 0# ## Sets Setpoint

40005 Tank Temperature 0# ## Passes tank temp from remote sensor

NOTE: To ensure proper operation re-send the conﬁ guration bits to holding register 40001 prior to issuing a command.

For proper hexadecimal conversion of rate percentage, please refer to the Rate and Temperature Conversion section on page 17 of this manual.

Cascade

In order to operate the Crest boiler in Cascade with ModBus communications, conﬁ gure the leader boiler per the demand conﬁ gurations in this manual. Connect the remaining boilers in the cascade through the normal cascade communications wiring. Cascade control can then be accomplished automatically through the leader boiler.

Please note that with ModBus communication connected to only the leader boiler, total Cascade information can be seen through the communications link. If you wish to see all the individual temperatures of each unit in the Cascade, each unit will have to have a ModBus communication board. However, each unit can be monitored without the need to control each one individually.

Monitoring Only

All Crest boilers are equipped with the ModBus communication board and can be set up to operate with its own internal controls. If necessary, ModBus can be conﬁ gured as a monitoring device by polling the ModBus board for the read only variables.

5 Unit Operation (continued)

ModBus Instructions

Rate and Temperature Conversions:

Rate

When issuing a rate command the rate can be communicated as percent modulation or a desired setpoint, depending on the setting of the BMS Type in the BMS Setup Menu.

The proper data format for the modulation percentage is the direct conversion to hexadecimal. This conversion can be accomplished through online number based converters or some scientiﬁ c calculators.

For Example:

Rate % HEX

000 20 14 45 2D 60 3C 80 50 95 5F

100 64

To send a desired setpoint, the hexadecimal value must be determined through linear interpolation of programmable parameters on the BMS Setup Menu:

- BMS temperature set-point at low analog input

- BMS temperature set-point at high analog input

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

BMS temperature setpoint at

low analog input

BMS temperature setpoint at

high analog input

DEFAULT

VALUES

Deg C Deg F Voltages

21 69.8 2

82 179.6 10

DEFAULT

For Example:

Send a setpoint of 110°F.

The formula to use for the interpolation is:

Rate Command =

(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=158 High Voltage =10 Low Voltage = 2

[(110-69.8)(10-2)/(179.6-69.8)] + 2 = 4.92 Volts

(4.92/10) x 100 = 49.2

49 = 31 Hexadecimal

A value of [00][31] in hexadecimal would be written to Holding register 40003 to issue a command for a 110°F setpoint.

Temperature

The Crest boiler passes temperature data in degrees Celsius. Also, to accommodate decimal places the decimal value must be divided by 10.

Here are the conversions to and from Celsius:

Example:

Outdoor temperature from remote sensor on BAS System = 80°F

80°F = 26.7°C Data that needs to be transmitted is 26.7 * 10 = 267

= (5/9) * (Tf-32) Tf = (9/5) * Tc+32

Decimal Binary HEX

267 100001011 10B

Outlet temperature from unit sensor = 155°F

155°F = 68.3°C Data transmitted from unit in HEX = 2AB = 683 683 ÷ 10 = 68.3 (°C)

Decimal Binary HEX

683 1010101011 2AB

6 Troubleshooting

ModBus Instructions

Should you encounter problems communicating over ModBus, the following items should be checked in this order:

1. Physical Layer

2. Communications Conﬁ guration and Port Settings

3. ModBus Error Codes

4. Unit Status / Blocking / Lockout Codes

Physical Layer

1. Check that all components have power (Boiler, Gateway, BAS Master)

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

3. Check proper shield grounding

4. Check A, B terminal connections

5. Check for Terminating Resistors (120 ohms)

6. Check for broken wires

Communications

1. Check Dip Switch Conﬁ guration of MTR-01 Board

2. Check Baud Rate (9600, 19200)

3. Check Parity

4. Check Slave ID

5. Check Port Setting on Master, Gateway, and Computers

Status Codes (Input Registers 30014 and 30023)

2 = Heat Demand blocked due to high absolute outlet temperature 3 = Heat Demand blocked due to high absolute ﬂ ue temperature 4 = Heat Demand blocked due to high absolute Delta T (Outlet - Inlet) 7 = Heat Demand blocked due to changed Personality Plug 8 = Heat Demand blocked due to Low 24 VAC 9 = Outdoor shutdown 10 = Block due to switch OFF boiler (ON/OFF of Display) 12 = Block due to line frequency 16 = Service function 19 = DHW function Storage Tank 21 = SH function Heat demand from Room Thermostat 22 = SH function Heat demand from Boiler Management System 23 = SH function Heat demand from Cascade 30 = Heat demand activated by Freeze Protection 32 = DHW Pump Delay 33 = SH Pump Delay 34 = No heat function (after pump delay) 40 = Lockout

ModBus Error Codes

1. Check ModBus communication for error codes (see page 6 for ModBus Exception Codes)

2. Check ModBus PDU

3. Check Slave ID

4. Check ModBus Command

5. Check Conﬁ guration bits for Holding Register 40001

6. Check Commands and data for Holding Registers 40002 - 40007

Unit Status Codes

See Codes in this section

Boiler Status

The Crest boiler displays a boiler state code on the Building Screen to help aid in troubleshooting. The boiler state indicates what the boiler is actually doing. This state should be compared to the command issued and what is expected. If the boiler state does not agree with the command issued, check communication and conﬁ guration.

Blocking Codes (Input Registers 30015 and 30024)

0 = No blocking 1 = SH blocking 2 = Blocking Due to Low 24 VAC Supply 3 = Blocking due to General block 4 = Blocking MRHL is open 5 = Blocking due to Switched OFF boiler (Display ENTER switch) 6 = Blocking due to wrong communication of Cascade 7 = Blocking due to High Delta 8 = Blocking due to High Flue Temperature 9 = Blocking due to low 24 VAC supply 10 = Blocking due to General Block 12 = Blocking due to to line frequency 13 = Blocking anti-cycling time 14 = Storage Tank demand Blocked due to Fan problems 15 = No system sensor connected and leader control present 16 = Blocking due to outlet temperature limit 17 = Fan min decreased due to low ﬂ ame current 18 = Limit max fan speed due to high Delta T 19 = Limit max fan speed due to high ﬂ ue temp 21 = Blocking due to Switched Off boiler 24 = Blocking due to high temperature rise 25 = Blocking due to high ﬂ ue temperature 26 = Blocking due to high outlet water temperature 27 = Blocking due to anti-cycling time 28 = Blocking due to changed ID Plug 32767 = Code not present

6 Troubleshooting (continued)

Lockout Codes Description

5 = Analog to Digital converter input had changed too quickly 7 = Rapid Temperature Change on Pre-Mix Sensor 2 (S14) 8 = Rapid Temperature Change on Pre-Mix Sensor 1 (S13) 9 = Rapid Temperature Change on Pre-Mix Sensor 2 (S12) 10 = Rapid Temperature Change on Pre-Mix Sensor 1 (S11) 11 = Analog to Digital converter input is changed too quickly 12 = Rapid Temperature Change on Flue Sensor (S10) 13 = Rapid Temperature Change on Outlet Sensor (S9) 15 = Rapid Temperature Change on System Return Sensor (S7) 16 = Rapid Temperature Change on System Supply Sensor (S6) 17 = Rapid Temperature Change on Tank Sensor (S4) 18 = Rapid Temperature Change on Flue Sensor (S3) 19 = Rapid Temperature Change on Inlet Sensor (S2) 20 = Rapid Temperature Change on Outlet Sensor (S1) 25 = Pre-Mix Sensor 2 (S14)-Short 26 = Pre-Mix Sensor 1 (S13)-Short 27 = Pre-Mix Sensor 2 (S12)-Short 28 = Pre-Mix Sensor 1 (S11)-Short 29 = Flue Sensor (S10)-Short 30 = Outlet Sensor (S9) – Short 32 = System Return Temperature Sensor (S7) – Short 33 = System Supply Temperature Sensor (S6) – Short 34 = Tank Sensor (S4) – Short 35 = Flue Sensor (S3) – Short 36 = Inlet Sensor – Short 37 = Outlet Sensor (S1) – Short 38 = Temperature Measurement Error 2 39 = Temperature Measurement Error 1 45 = High temperature differential between S12 and S14 46 = High temperature differential between S11 and S13 48 = High temperature differential between S3 and S10 49 = High temperature differential between S1 and S9 50 = Internal Error 129 = Large Pre-Mix Temperature High 130 = Small Pre-Mix Temperature High 134 = Louvers Not Open 135 = Louvers Not Closed 137 = Large Blower Proving Switch Not Closed 139 = Large Blower Proving Switch Not Open 140 = Small Blower Proving Switch Not Open 145 = Large Blower Proving Switch Not Closed 146 = Small Blower Proving Switch Not Closed 148 = Large Blower Proving Switch Not Open 149 = Large Fan Speed Too Low 150 = Large Fan Speed Too High 163 = Wrong Personality Plug 164 = Flame Current Circuit Failed 166 = Auto Reset High Limit 167 = Blocked Drain Switch Open 169 = Gas Pressure Switch Open 170 = Low Water Cut-Off Open 177 = Flue Sensor Short 178 = Flue Sensor Open 179 = Inlet Sensor Short 180 = Inlet Sensor Open

ModBus Instructions

6 Troubleshooting

Lockout Codes Description

192 = Outlet Sensor Short 193 = Outlet Sensor Open 201 = Internal Error 204 = Internal Error 205 = Parameters Programmed 206 = Error while programming Parameters 207 = Internal Error 228 = Pre-Mix Sensors Temperature Differential Too High 229 = Flame Failure 2 230 = Small Fan Speed Low 231 = Small Fan Speed High 232 = Flame Failure 1 233 = Ignition Failure 236 = Flue Damper Open 235 = Small Blower Proving Switch Not Open 236 = Small Blower Proving Switch Not Closed 238 = Air Pressure Switch Open 239 = Flame 1 Out of Sequence 240 = External Manual Reset High Limit 241 = Flame 2 Out of Sequence 244 = Large Gas Valve Relay Failure 245 = Small Gas Valve Relay Failure 246 = Internal Manual Reset High Limit 247 = High Flue Temperature 253 = High Combustion Air Temperature 254 = Display Fault

ModBus Instructions

6 Troubleshooting (continued)

ModBus Instructions

Installation / Replacement Procedure

1. Turn OFF the main electrical power to the appliance.

2. Turn OFF the main manual gas shutoff to the appliance.

3. Unplug the three (3) wire harnesses on the MTR01 control board (see FIG. 6-1).

4. Unscrew the four (4) mounting nuts on the MTR01 control board and set aside. Remove the MTR01 control board (see FIG. 6-2).

5. Replace / install the new MTR01 control board.

6. Replace the four (4) mounting nuts removed in Step 4.

7. Reconnect all three (3) wire harnesses unplugged in Step

8. Turn on the main electrical power and the main manual gas shutoff to the appliance.

9. Conﬁ gure the MTR01 control board and unit controls per this manual and resume operation.

Figure 6-1_MTR01 Control Board

UNPLUG THREE (3) WIRE HARNESSES

Figure 6-2_Control Panel w/MTR01 Control Board

UNSCREW THE FOUR (4) MOUNTING NUTS ON THE MODBUS CONTROL BOARD (MTR01) AND SET ASIDE TO SECURE THE NEW MTR01 CONTROL BOARD TO THE CONTROL PANEL

7 Diagrams

Figure 7-1 Ladder Diagram

120VAC NEUTRAL

TERMINAL STRIP 120V SUPPLY "L"

ON/OFF

SWITCH

X1-6

X6-1

X2-5

SMALL BLOWER

LARGE BLOWER

LWCO

PROBE

GPS1 GPS2 GPS3

BLOWER PROVING

SWITCH (LARGE)

BLOWER PROVING

SWITCH (SMALL)

BLOCKED FLUE

BLOCKED DRAIN

3.15 AF45.0 A

RELAY

X1-1

LWCO RESET

SWITCH

"X5"

BLOCK WIRING

IS MODEL

DEPENDANT

INTEGRATED CONTROL

SYSTEM PUMP

RELAY

BOILER PUMP

RELAY

DHW PUMP

RELAY

SMALL GAS

VALVE RELAY

LARGE GAS

VALVE RELAY

LARGE GAS

VALVE RELAY

SMALL GAS

VALVE RELAY

X11

USB

INTERFACE

SMALL BLOWER

MODBUS

X1-3

FLUE DAMPER

J3-6

TEST

J3-3

SWITCH

J2-1

J2-2

X6-5

X6-15

X6-12

X13-1

X6-6

X5-1

X5-7

X5-2

X5-8

X5-3

X5-9

X5-4

X5-10

X5-5

X5-41

X5-6

X5-12

JUNCTION BOX

X1-2

TRANSFORMER

X1-3

X1-12

X1-1

X1-2

X1-4

X1-8

X2-4

X10-3

X10-6

X10-5

X10-4

X1-3

X1-7

X1-10

X2-5

X6-3

X6-10

X13-4

FLUE DAMPER

TRANSFORMER

24V

LWCO

BOARD

INTEGRATED

CONTROL

1.5A EACH MAX

TERMINAL STRIP

SYSTEM PUMP

BOLIER PUMP

SMALL BLOWER

RELAY

LARGE BLOWER

2-01X1-01X

RELAY

GAS

VALVE

(LARGE)

SPARK

GENERATOR

LARGE BLOWER

J3-5

J3-2

J3-4

X3-3

X3-4

X3-1

X3-2

X6-11

X6-2

X6-14

X6-13

X6-4

BOX DEPICTS

MODBUS

BOARD

-T

CN1

ALARM CONTACTS

RUN-TIME CONTACTS

TANK THERMOSTAT

ENABLE

LOUVER PROVING

24 VAC LOUVER RELAY COIL

AUX SWITCH 1

AUX SWITCH 2

OPTIONAL ITEMS

BOX DEPICTS

DUAL SENSOR

SINGLE HOUSING

CONNECTION BOARD

CN6-3

X6-3

X6-1

CN6-2

X6-2

CN6-1

CN3-6

CN3-7

CN3-14

CN3-13

CN3-12

CN3-11

CN3-10

CN3-9

CN3-8

CN3-1

CN3-2

CN3-3

CN3-4

SMALL BLOWER

LARGE BLOWER

CN3

DU941

LOW VOLTAGE

120 VAC

HIGH VOLTAGE

LARGE

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

TERMINAL STRIP 120V SUPPLY "N"

GROUND

CONTACTOR

DHW PUMP

CONTACTOR

VALVE

(SMALL)

GAS

INTEGRATED

CONTROL

FLAME

SENSE 2

SPARK

ROD

FLAME

SENSE 1

CONNECTION BOARD

CN1-4

CN1-5

CN1-6

CN1-12

CN1-10

CN1-11

CN1-9

CN1-8

CN1-7

CN1-1

HIGH LIMIT

CN1-2

SWITCH

CN1-3

Notes:

1. All wiring must be installed in accordance with: local, state, provincial and national code requirements per either N.E.C. in USA or C.S.A. in Canada.

2. If any original equipment wire as supplied with the appliance must be replaced, it must be replaced with wire having same wire gauge (AWG) and rated for a minimum of 105°C. Exceptions: Replacement high v oltage spark lead and ribbon cables must be purchased from the factory. Use of a non-approved spark lead or ribbon cables can lead to operational problem s which could result in non-repairable damage to the integrated controller or other components.

3. Actual connector block locations may vary from those shown on diagrams. Refer to actual com ponents for proper connector block locations when using diagrams to troubleshoot unit.

SMALL

X8-20

X8-10

X7-8

X7-7

X8-13

X8-14

X8-12

X8-11

X8-5

X8-15

X8-6

X8-16

X8-7

X8-17

X8-1

X8-3

X8-8

X8-2

X8-4

X8-9

X7-1

X7-5

X7-2

X7-6

X6-18

X6-9

X6-17

X6-8

X13-2

X13-3

10 11 12 13 14 15 16

1 2 3 4 5 6 7 8 9

X4-1

X4-2

X4-3

INLET SENSOR

OUTLET SENSOR (S9)

OUTLET SENSOR (S1)

FLUE SENSOR

FLUE SENSOR (S10)

PRE-MIX SENSOR 1 (S11)

PRE-MIX SENSOR 1 (S13)

PRE-MIX SENSOR 2 (S12)

PRE-MIX SENSOR 2 (S14)

RIBBON CABLE

R W

ModBus Instructions

SHIELD

MODBUS OPTION

SHIELD

RATE

0-10V

OUT

BOILER

0-10V

PUMP OUT

SYSTEM RETURN SENSOR

SYSTEM SUPPLY SENSOR

TANK SENSOR

OUTDOOR SENSOR

BMS

0-10V

SYSTEM

0-10V

PUMP IN

SHIELD

CASCADE

SHIELD

LCD

DISPLAY

LADDER DIAGRAM

LBL20182 REV A

7 Diagrams (continued)

Figure 7-2 Wiring Diagram

0-10V

LCD

DISPLAY

LARGE CONNECTION BOARD

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

DU941

SMALL CONNECTION BOARD

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16

LWCO PROBE

SHIELD

MODBUS

OPTION

SHIELD

RATE

OUT

BOILER

PUMP OUT

SYSTEM RETURN

SENSOR

SYSTEM SUPPLY

SENSOR

TANK

SENSOR

OUTDOOR

SENSOR

BMS

SYSTEM PUMP IN

SHIELD

CASCADE

SHIELD

ALARM

CONTACTS

RUN-TIME

CONTACTS

THERMOSTAT

ENABLE

LOUVER

PROVING

24 VAC LOUVER

RELAY COIL

SWITCH 1

SWITCH 2

TANK

AUX

MODBUS

BOARD

X1-1 X1-2

X1-3 CN6-3 CN6-2 CN6-1

CN3-6 CN3-7

CN3-14 CN3-13 CN3-12 CN3-11 CN3-10

CN3-9 CN3-8 CN3-1 CN3-2 CN3-3 CN3-4

CN3

CN1

CN1-4 CN1-5 CN1-6

CN1-12 CN1-10 CN1-11

CN1-9 CN1-8 CN1-7 CN1-1 CN1-2 CN1-3

TEST

SWITCH

OR/BK

LWCO RESET

GPS1 GPS2 GPS3

BLOWER PROVING

SWITCH (LARGE)

BLOWER PROVING

SWITCH (SMALL)

BLOCKED FLUE

SWITCH

BLOCKED DRAIN

SWITCH

X6-3

X6-1

X6-2

X4-1

X4-2

X4-3

INLET SENSOR

OUTLET SENSOR (S9)

OUTLET SENSOR (S1)

FLUE SENSOR

FLUE SENSOR (S10)

PRE-MIX SENSOR 1 (S11)

PRE-MIX SENSOR 1 (S13)

PRE-MIX SENSOR 2 (S12)

PRE-MIX SENSOR 2 (S14)

HIGH LIMIT

SWITCH

LWCO

BOARD

J3-6 J3-5

J3-4 J3-3

OR/BK

J3-2 J2-1

OR OR

J2-2

"X5"

BLOCK WIRING

IS MODEL

DEPENDANT

ModBus Instructions

BOX DEPICTS

OPTIONAL ITEMS

BOX DEPICTS DUAL SENSOR

SINGLE HOUSING

LOW VOLTAGE

ON/OFF SWITCH

BK/W

120V

SUPPLY

GND

120 VAC

BK/W

TRANSFORMER

HIGH VOLTAGE

1.5A EACH MAX

GAS VALVE (SMALL)

GAS VALVE (LARGE)

BLOWER

(SMALL)

1245

R/W

BLOWER

(LARGE)

245

FLAME SENSE 2

SPARK ROD

FLAME SENSE 1

FLUE DAMPER

24V

SYSTEM PUMP CONTACTOR

BOILER PUMP CONTACTOR

DHW PUMP CONTACTOR

JUNCTION

BOX

G/W

GND

INTEGRATED CONTROL

X8-20

X8-10

BL R BL R BR

OR/W

W BL

BK Y

-T

R OR OR BL BK BR

Y OR

X7-8 X7-7 X8-13 X8-14 X8-12 X8-11 X8-5 X8-15 X8-6 X8-16 X8-7 X8-17 X8-18 X8-1

X8-3

X8-8

R/W

X8-2

X8-4

X8-9

X7-1

X7-5

X7-2

X7-6

X3-3 X3-4 X3-1 X3-2 X6-1 X6-11 X6-2 X6-14 X6-10 X6-13

X6-4

X6-3

X6-5

X6-15

X6-12

X13-1

X6-6

X5-1 X5-7 X5-2 X5-8 X5-3 X5-9 X5-4 X5-10 X5-5 X5-41 X5-6 X5-12

X1-6

X1-3 X1-12 X10-1 X10-4

X1-1

X1-2

X1-4 X10-2

X10-5 X10-3

X10-6 X6-18

X6-8

X1-8

X6-9 X6-17

X2-4

X13-2 X13-3

X2-3

X1-7 X1-10

X1-5

X2-5

X13-4

X11

USB

INTERFACE

T OR

R BK

SMALL

BLOWER

RELAY

LARGE

BLOWER

RELAY

W/BK

GENERATOR

R P

FLUE DAMPER

TRANSFORMER

SPARK

Notes:

1. All wiring must be installed in accordance with: local, state, provincial and national code requirements per either N.E.C. in USA or C.S.A. in Canada.

2. If any original equipment wire as supplied with the ap pliance must be replaced, it must be replaced with wire having sa me wire gauge (AWG) and rated for a minimum of 105°C. Exceptions: Replacem ent high voltage spark lead and ribbon cables must be purchas ed from the factory. Use of a non-approved spark lead or ribbon cables can lead to operational problems which c ould result in non-repairable damage to the integrated controller or other components.

3. Actual connector block locations may vary from those shown on diagrams. Refer to actual component s for proper connector block locations when using diagrams to troubleshoot unit.

WIRING DIAGRAM

LBL20181 REV A

Revision Notes: Revision A (ECO #C08179) initial release.

FB-MODB Rev A

06/11

Crest Audio 3.5 Instructions Manual

Specifications and Main Features

Frequently Asked Questions

User Manual