Lochinvar Knight 81 User manual

MODB-I-O_100161545_2000014822_Rev M
is manual must only be used by a
quali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.
WARNING
Save this manual for future reference.
MODBUS AND BACNET
COMMUNICATION
INSTRUCTIONS
Models:
Knight 81 - 286, Knight XL 400 - 801,
Armor 151 - 801, Outdoor Knight 151
- 286, Outdoor Knight XL 400 - 801,
Outdoor Armor 151 - 801,
AQUAS 400 - 801, FTXL 400 - 850,
Wall Mount 51 - 211, Wall Hung 55 -
399, and Wall Mount Armor 125 - 200

Contents
1. INTRODUCTION
Definitions .................................................................... 2
Minimum System Requirements.................................. 2
2. INSTALLATION
Wall Mount, Armor, Knight and Knight XL, Outdoor
Armor, Outdoor Knight, and Outdoor Knight XL........ 3-4
FTXL ............................................................................ 5
Wall Hung .................................................................... 6
3. MODBUS CONFIGURATION
Addressing................................................................... 7
Timing Specifications................................................... 8
Parity............................................................................ 8
Data Transmission Mode............................................. 8
ModBus Board Diagnostics ......................................... 8
Internal Faults......................................................... 8
ModBus Function Set .................................................. 9
ModBus Exception Codes ........................................... 10
4. MODBUS MEMORY MAP
Primary Data Tables.................................................... 11
Memory Map............................................................11-12
Input Registers ....................................................... 12
Holding Registers................................................... 12
Configuration Bits......................................................... 12
5. BACNET CONFIGURATION....................................... 13
Addressing................................................................... 13
Timing Specifications................................................... 14
Communication Board Diagnostics ............................. 14
Internal Faults......................................................... 14
6. BACNET MEMORY MAP
Primary Data Tables.................................................... 15
Crest Boiler Memory Map........................................15-16
Input Registers ............................................................ 15
Holding Registers................................................... 16
7. WIRING REQUIREMENTS
Physical Wiring ............................................................ 17
Control Inputs/Outputs............................................ 18-19
Control Location.......................................................20-21
Typical Boiler/Water Heater System Wiring................ 22
8. UNIT OPERATION
Unit Operation with ModBus
Communications..................................................... 23-27
9. TROUBLESHOOTING........................................... 28-29
10. DIAGRAMS
Ladder & Wiring Diagrams ..................................... 30-39
Revision Notes ................................................... Back Cover
Abbreviation or Acronym Meaning
ASCII American Standard Code for Information Interchange
BACnet A data communication protocol for Building Automation and Control Networks
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 Significant Byte
ModBus A serial, half-duplex data transmission protocol developed by AEG Modicon
MSB Most Significant Byte
RS232 A standard for serial, full-duplex (FDX) transmission of data based on the RS232
Standard
RS485 A standard for serial transmission of data based on the RS-485 Standard
RTU Remote Terminal Unit
1 Introduction
e information contained in this manual provides general guidelines for the implementation of ModBus and BACnet
communication with the Lochinvar Armor water heaters (151 - 801), Wall Mount Armor (125-200), Knight (81-286), Knight
XL (400 - 801), Outdoor Knight (151-286), Outdoor KnightXL (400-801), Outdoor Armor (151-801), Wall Mount (51 - 211),
and Wall Hung (55 - 399) boilers.
All ModBus networks are implemented utilizing a master-slave arrangement where all boilers/water heaters are slaves and
the master is a building automation system capable of communicating over a RS-485 half duplex serial connection. BACnet
networks are implemented using a token passing process where multiple masters and slaves share a common RS-485 bus. e
Lochinvar BACnet interface is a master only.
Definitions
Minimum System Requirements
• BAS system or computer with a serial or USB port
with a converter to RS-485 half duplex.
• Unit equipped with communication board.
• Shielded twisted pair communication cable.

3
2 Installation
ModBus and BACnet Communication Instructions
Installation procedure - for Models WB,
WA, AW, KB, OA, OK and KBX
1. Turn OFF the main electrical power to the appliance.
2. Turn OFF the main manual gas shuto to the appliance.
3. Assemble the communication control board to the sheet
metal base as shown in FIG. 2-1a and 2-1b, depending on
model.
4. Connect the power harness from the appliance to the
communication board through the sheet metal cover
hole (see FIG. 2-2a and 2-2b, depending on model).
5. Using the two (2) sheet metal screws provided in the kit,
attach the pre-painted sheet metal cover over the
Communication board for protection from line voltage
(FIG. 2-2a and 2-2b, depending on model).
6. Locate the pilot holes on the side of the jacket (le side if
AW/KB/KXL or right side if WB/WA), using the sheet
metal screws provided in the kit, mount the
communication board assembly to the appliance (FIG.
2-3a and 2-3b, depending on model).
Wiring
7. Disconnect power to the transformer by removing
connection “B”, see FIG. 2-4, page 4.
8. Connect A, C, D, and B (FIG. 2-4).
9. Connect the communication board to the control board
of the appliance (see FIG. 2-5 on page 4).
10. Turn on the main electrical power and the main manual
gas shuto to the appliance.
11. Congure the control board and unit controls per this
manual and resume operation.
MOUNT PRE-PAINTED
SHEET METAL COVER
OVER THE MODBUS
ASSEMBLY FOR PROTECTION
FROM LINE VOLTAGE
MODBUS
ASSEMBLY
ATTACH POWER HARNESS
TO MODBUS THROUGH
SHEET METAL COVER HOLE
Figure 2-2a_Attach Cover to Communication Board for
Models WB, WA, AW, KB and KBX
BLT7068 [X4]
BLT2007 [X4]
SHEET METAL BASE
JKB40095
Figure 2-1a_Assemble Communication Board for
Models WB, WA, AW, KB and KBX
NOTE: KB/KXL/AW - MOUNT MODBUS ASSEMBLY TO THE LEFT SIDE OFTHE
JACKET. WB/WA - MOUNT MODBUS ASSEMBLY TO THE RIGHT SIDE OF THE JACKET.
- LOCATE THE PILOT HOLES
- USING THE 4 SHEET METAL SCREWS
PROVIDED IN THE KIT MOUNT THE MODBUS
ASSEMBLY TO THE UNIT
(SIDE DEPENDENT ON MODEL)
Figure 2-3a_Mount Communication board to Unit for
Models WB, WA, AW, KB and KBX
SHEET METAL
BASE (JKB40265)
BLT2007
[X4]
BLT7068 [X4]
IMG00565
Figure 2-2b_Attach Cover to Communication Board
for Models OA and OK
IMG00566
MODBUS
ASSEMBLY
MOUNT PRE-PAINTED
SHEET METAL COVER OVER
THE MODBUS ASSEMBLY FOR
PROTECTION FROM LINE VOLTAGE
ATTACH POWER HARNESS
TO MODBUS THROUGH
SHEET METAL COVER HOLE
BLT7404 [X4]
IMG00567
- LOCATE THE PILOT HOLES
- USING THE (2) SHEET METAL SCREWS PROVIDED
IN THE KIT MOUNT THE MODBUS ASSEMBLY TO THE UNIT
(SIDE AND ORIENTATION DEPENDENT ON MODEL /
VERTICAL ORIENTATION SHOWN)
NOTE: OA/OK151 MOUNT MODBUS ASSEMBLY TO THE RIGHT SIDE JACKET FLANGE
OA/OK400-501 MOUNT MODBUS ASSEMBLY IN HORIZONTAL ORIENTATION
Figure 2-1b_Assemble Communication Board for
Models OA and OK
Figure 2-3b_Mount Communication board to Unit for
Models OA and OK

4
ModBus and BACnet Communication Instructions
2 Installation
B
G
W
FROM POWER
HARNESS
B
W
TO TRANSFORMER
B
W
ACDB
W
G
B
R
G
BL
G
GY
ROUTE THROUGH
JACKET HARNESS
CLIPS
USE SUPPLIED CABLE TIE
TO CONNECT MODBUS POWER
HARNESS TO BLOWER POWER
WIRES (RED, WHITE, GREEN)
Figure 2-4_Harness Connections_WB, WA, AW, KB, KBX, OA, and OK models
CONNECT TO
CONNECTION BOARD
FROM COMMUNICATION
BOARD*
CONNECT TO
CONTROL BOARD
FROM COMMUNICATION
BOARD*
LOW VOLTAGE
CONNECTION BOARD
*HARNESSES CAN ONLY BE CONNECTED ONE WAY.
Figure 2-5_Connect Communication Board to Control Board

IMG01107
4X LOCKNUT
2X RIVET
2X CLIP
4X ALUMINUM
SPACER
Figure 2-6a_Assemble ModBus Control Board for FTXL
1. Turn OFF the main electrical power to the appliance.
2. Turn OFF the main manual gas shuto to the appliance.
3. Assemble the ModBus control board and provided cable
clamps to the control panel as shown in FIG. 2-6a.
4. Connect the ModBus power, control board and
connection board wiring harnesses. Secure the wiring
with the provided cable clips and route it through the
bottom of the control panel. Perform the wiring
connections referencing FIG.’s 2-6b and 2-6c.
5. Turn ON the main electrical power to the appliance.
6. Congure the control board and unit controls per this
manual and resume operation.
IMG01106
SECURE CONNECTION
BOARD W/ 5X CLIPS
TRANSFORMER
PRIMARY 120V
UNIT
POWER HARNESS
MODBUS
POWER HARNESS
PRIMARY
120V
LOW VOLTAGE CONNECTION BOARD
SECURE HARNESS
W/ 3X CLIPS
MODBUS
MAIN CONTROL BOARD
CONNECTION BOARD /
MODBUS HARNESS
SECURE HARNESS
W/ 2X CLIPS
UNIT POWER HARNESS
MODBUS
POWER HARNESS
IMG01105
Figure 2-6b_Secure Control Board to FTXL Unit
Figure 2-6c_Perform Wiring Connections for FTXL
ModBus installation procedure - for FTXL Models
ModBus and BACnet Communication Instructions
2 Installation (continued)
5

6
2 Installation
ModBus and BACnet Communication Instructions
Installation Procedure - for WH Models
1. Turn OFF the main electrical power to the appliance.
2. Turn OFF the main manual gas shuto to the appliance.
3. To assemble the communication board to the sheet metal,
insert four (4) standos into the front access panel
(FIG. 2-6).
4. Place the communication board onto the standos
installed in Step 3. Use the screw (provided in kit) to
secure the control panel cover (FIG. 2-6).
5. Connect the wire harnesses (100172824 , 100172826 and
100172828) from the appliance to the communication
board following the diagram shown in FIG. 2-7.
6. Turn on the main electrical power and the main manual
gas shuto to the appliance.
7. Congure the communication board and unit controls
per this manual and resume operation.
Figure 2-7_Harness Connections_WH
INSERT
STANDOFFS
USE SCREW TO
SECURE COVER
TO FRONT PANEL
Figure 2-6_Assemble Communication Board_WH
RBL
G
W
B
GY
G
W
B
B
G
W
(WRE20077)
(WRE20073)
(WRE20075)

7
3 ModBus Configuration
ModBus and BACnet Communication Instructions
Addressing
e ModBus addressing space is comprised of 256 dierent
addresses.
• 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.
Each switch set to the 1 position 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. e 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
e ModBus communication board is equipped with a set of ten dip switches that are used to set the board conguration
(address, baud rate, and parity settings). e rst eight are used to set the address of each board. e ninth is baud rate. e
tenth is parity.
LED’S
DIP SWITCHES
Figure 3-1_ModBus Communication Board

8
3 ModBus Configuration
ModBus and BACnet Communication Instructions
Timing Specifications
e 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. e maximum delay between frames is 1.5 character
times.
When the system temperature, tank temperature, and/or
0-10V BMS voltage is provided by the BAS to the boiler, it
is critical that the values be updated every few seconds. If
the boiler does not receive updated values within a timeout
period (installer adjustable), the control will revert to using its
own readings (if connected). e timeout is programmable
as follows:
1. Press and hold the LEFT SELECT [MENU] key for 5
seconds.
2. Enter installer code - 5309.
3. Scroll down and select [CONTROL MODES].
4. Scroll down and select [MODBUS T/O].
5. Scroll to desired time. Press the RIGHT SELECT [SAVE]
key.
e timeout is adjustable between 5 and 120 seconds. e
default timeout is 10 seconds.
When the BAS is not providing any of these values, but
is still controlling the boiler (such as providing an enable
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 con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 e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
e 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 transmission of data. e other yellow
LED (D6) is used to indicate reception of data. e 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 o
No ModBus Communication = 1.5 seconds on, 0.5 seconds
o
ModBus Communication
e ModBus communication commands and exception codes
that are supported by the ModBus communication board can
be found on pages 8 and 9 of this manual.
Please note that the brackets ([]) denote
screen status.
NOTICE

9
3 ModBus Configuration (continued)
ModBus and BACnet Communication 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 Diagnostic - Clear Counters and Diagnostic
Registers
11 0B Diagnostic - Return Bus Message Count
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
ModBus Function Set

10
3 ModBus Configuration
ModBus and BACnet Communication Instructions
MODBUS Exception Codes
Code Name Meaning
01 ILLEGAL FUNCTION
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
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 unconfigured and is being asked to return register values.
02 ILLEGAL DATA ADDRESS
The data address received in the query is not an allowable address for the
server (or slave). More specifically, the combination of reference number and
transfer length is invalid. For a controller with 100 registers, the PDU addresses
the first register as 0, and the last one as 99. If a request is submitted 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.
03 ILLEGAL DATA VALUE
A value contained in the query data field 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 specifically 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 significance of any particular value of any particular register.
04 SLAVE DEVICE FAILURE An unrecoverable error occurred while the server (or slave) was attempting to
perform the requested action.
05 ACKNOWLEDGE
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.
06 SLAVE DEVICE BUSY
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.
08 MEMORY PARITY ERROR
Specialized use in conjunction with function codes 20 and 21 and reference type
6, to indicate that the extended file area failed to pass a consistency check. The
server (or slave) attempted to read record file, 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
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
misconfigured or overloaded.
0B GATEWAY TARGET DEVICE
FAILED TO RESPOND
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 Exception Codes

4 ModBus Memory Map
ModBus and BACnet Communication Instructions
11
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
Memory Map
Coils
Address Description Default Unit Min. Max. Resolution
00001 Room Thermostat 1 0 1=ON / 0=OFF 0 1 1
00002 Room Thermostat 2 0 1=ON / 0=OFF 0 1 1
00003 Room Thermostat 3 0 1=ON / 0=OFF 0 1 1
00005 Tank Thermostat 0 1=ON / 0=OFF 0 1 1
Discrete Inputs
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 Air Pressure Switch 0 1=ON / 0=OFF 0 1 1
10006 Blocked Drain Switch 0 1=ON / 0=OFF 0 1 1
10007 Auto Reset High Limit 0 1=ON / 0=OFF 0 1 1
10008 Flame 0 1=ON / 0=OFF 0 1 1
10009 Room Thermostat 1 0 1=ON / 0=OFF 0 1 1
10010 Tank Thermostat 0 1=ON / 0=OFF 0 1 1
10024 Room Thermostat 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 CH Pump 0 1=ON / 0=OFF 0 1 1
10036 DHW Pump 0 1=ON / 0=OFF 0 1 1
10037 Louver Relay 0 1=ON / 0=OFF 0 1 1
10038 Gas Valve 0 1=ON / 0=OFF 0 1 1
10039 System Pump 0 1=ON / 0=OFF 0 1 1
10044 DHW Recirculation Pump 0 1=ON / 0=OFF 0 1 1

12
4 ModBus Memory Map
ModBus and BACnet Communication Instructions
Input Registers
Address Description Default Unit Min. Max. Resolution
30001 Discrete Inputs 1 - 16 0 HEX 0 65535 1
30002 Discrete Inputs 17 - 32 0 HEX 0 65535 1
30003 Discrete Inputs 33 - 48 0 HEX 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 HEX 0 65535 1
30015 Boiler Blocking Code 0 HEX 0 65535 1
30016 Boiler Lockout Code 0 HEX 0 65535 1
Holding Registers
40001 Configuration 0 NA 0 65535 1
40002 Coils 0 NA 0 65535 1
40003 0-10 Volt Input / Rate Command / Setpoint
Command 0 % 0 100 1
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 DHW Recirculation Temperature 0 Degrees Celsius -20 130 0,1
Memory Map
Configuration Bits
Address 40001 contains conguration bits sent from the BAS to the appliance. ese bits tell the boiler/water heater to use its
own internal inputs, or inputs from the BAS. When a bit is set to 1, the boiler/water heater will ignore the corresponding value
contained internally, and expect the BAS to write that value into the Holding Registers. e conguration bits are as follows:
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)
Bit 0 (LSB): Boiler Enable
Bit 1: Tank ermostat
Bit 2: Rate Command / 10 - 10V Input / Setpoint Command
Bit 3: Tank Setpoint

5 BACNET Configuration
Modbus Instructions
ModBus and BACnet Communication Instructions
Addressing
e BACnet local addressing space is comprised of 256
dierent addresses.
• 255 is reserved for broadcast messages from a
master device.
• 128 - 254 are free to use for slave devices only.
• 0 - 127 are free to use for master or slave devices.
Since the BACnet communication board is a BACnet master,
address 127 is the highest address that can be used.
To set the BACnet local 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.
Each switch set to the 1 position 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 BACnet board to 50, dip switches
2, 5, and 6 have to be set to the 1 position. e 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
e BACnet Device Instance is calculated by adding the
BACnet local address to 600000. Using the above example, the
Device Instance will be:
Device Instance = 600000 + 50 = 600050
e base address (600000 in this example) is model dependant
and can be changed by the integrator. It can be set to any value
between 0 and 4194048. e resulting device instance will be
this value + the local address, as before. Once the base address
is changed, it can be reset back to the default base address
(600000 in this example) using the following procedure:
1. Turn OFF power to the interface board.
2. Set Dip switches 1 - 8 to the 1 position.
3. Turn ON power to the interface board.
4. Aer a few seconds, turn OFF power to the interface board.
5. Set Dip switches 1 - 7 to the desired local address. Set Dip
switch 8 to the 0 position.
6. Turn ON power to the interface board.
Device Name
e default device name is “MTR-01 BACnet.” is can be
changed by the integrator as desired.
e BACnet communication board is equipped with a set of ten dip switches that are used to set the board conguration (address
and baud rate). e rst eight are used to set the address of each board. e ninth and tenth are baud rate.
LED’S
DIP SWITCHES
Figure 5-1_Communication Board
13

5 BACnet Configuration
Modbus Instructions
ModBus and BACnet Communication Instructions
Timing Specifications
e baud rate for the BACnet board is selectable with Dip
switches #9 and #10.
Communication Board Diagnostics
e Communication 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 transmission of data. e
other yellow LED (D6) is used to indicate reception of data.
e 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 o
No BACnet Communication = 1.5 seconds on, 0.5 seconds
o.
Please note that the brackets ([]) denote
screen status.
NOTICE
Switch #9 Switch#10 Baud Rate
OFF OFF 9600
ON OFF 19200
OFF ON 38400
ON ON 76800
When the system temperature, tank temperature, and/or
0-10V BMS voltage is provided by the BAS to the boiler, it
is critical that the values be updated every few seconds. If
the boiler does not receive updated values within a timeout
period (installer adjustable), the control will revert to using its
own readings (if connected). e timeout is programmable
as follows:
1. Press and hold the LEFT SELECT [MENU] key for 5
seconds.
2. Enter installer code - 5309.
3. Scroll down and select [CONTROL MODES].
4. Scroll down and select [MODBUS T/O].
5. Scroll to desired time. Press the RIGHT SELECT [SAVE]
key.
e timeout is adjustable between 5 and 120 seconds. e
default timeout is 10 seconds.
When the BAS is not providing any of these values, but
is still controlling the boiler (such as providing an enable
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.
14

ModBus and BACnet Communication Instructions
6 BACnet Memory Map
Primary Data Tables
Object Type Data Type Read / Write
Binary Input (BI) Single Bit Read Only
Binary Value (BV) Single Bit Read / Write
Analog Input (AI) 16-Bit Word Read Only
Analog Value (AV) 16 Bit Word Read / Write
Memory Map
Object Name Object
Type
Object
Instance Units Min Max Resolution
Binary Values
Boiler Enable / Room Th. 1 BV 0 none 0 1 1
Room Th.2 BV 1 none 0 1 1
Room Th.3 BV 2 none 0 1 1
Tank Thermostat BV 4 none 0 1 1
Binary Inputs
Flow Switch BI 1 none 0 1 1
Gas Pressure Switch BI 2 none 0 1 1
Louver Proving Switch BI 3 none 0 1 1
Air Pressure Switch BI 4 none 0 1 1
Blocked Drain Switch BI 5 none 0 1 1
Auto Reset High Limit BI 6 none 0 1 1
Flame BI 7 none 0 1 1
Room Thermostat 1 BI 8 none 0 1 1
Tank Thermostat BI 9 none 0 1 1
Room Thermostat 2 BI 23 none 0 1 1
Run Time Contacts BI 32 none 0 1 1
Alarm Contacts BI 33 none 0 1 1
Boiler Pump BI 34 none 0 1 1
DHW Pump BI 35 none 0 1 1
Louver Relay BI 36 none 0 1 1
Gas Valve BI 37 none 0 1 1
System Pump BI 38 none 0 1 1
Inputs
BI Inputs 0 - 15 AI 0none 0 1 1
BI Inputs 16 - 31 AI 1 none 0 1 1
BI Inputs 32 - 47 AI 2 none 0 1 1
System / Cascade Setpoint AI 3 Deg C 0 1 0.5
System Pump Speed AI 4 Percent 0 1 1
Cascade Total Power AI 5 Percent 0 1 1
Cascade Current Power AI 6 Percent 0 1 1
Outlet Setpoint AI 7 Deg C 0 1 0.5
Outlet Temperature AI 8 Deg C 0 1 0.1
Inlet Temperature AI 9 Deg C 0 1 0.1
15

Modbus Instructions
4 Wiring Requirements (continued)
ModBus and BACnet Communication Instructions
6 BACnet Memory Map
Object Name Object
Type
Object
Instance Units Min Max Resolution
Flue Temperature AI 10 Deg C -20 130 0.1
Firing Rate AI 11 Percent 0 100 1
Boiler Pump Speed AI 12 Percent 0 100 1
Boiler Status Code AI 13 none 0 65535 1
Boiler Blocking Code AI 14 none 0 65535 1
Boiler Lockout Code AI 15 none 0 65535 1
Analog Values
Configuration AV 0 none 0 65535 1
BV 0-4 AV 1 none 0 65535 1
0-10V BMS Input AV 2 Percent 0 100 1
Tank Setpoint AV 3 Deg C 0 87.5 0.5
Tank Temperature AV 4 Deg C -20 130 0.1
Outdoor Temperature AV 5 Deg C -40 60 0.1
System Supply Temperature AV 6 Deg C -20 130 0.1
Memory Map (continued)
16

7 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)
NOTE: Cable must be terminated with 120 ohm impedance matching resistor on each end.
A + (positive)
B - (negative)
Note that when the System Supply Temperature and/or the Tank Temperature are provided by the BAS, they need to be
refreshed every few seconds. is is required in order to prevent unwanted 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
Figure 7-1_Terminal Strip Connections
LOUVER RELAY
FLOW SWITCH
TANK THERMOSTAT
ROOM THERMOSTAT 3
SYSTEM SUPPLY SENSOR
BUILDING
MANAGEMENT
SYSTEM
LOUVER
PROVING SWITCH
COM
NO
LOW WATER
CUTOFF OUTDOOR SENSOR
TANK SENSOR
SHIELD SHIELD
TO
NEXT
BOILER
A
B
A
B
FROM
PREVIOUS
BOILER
ROOM THERMOSTAT 1
ROOM THERMOSTAT 2
AB
NOTE:
CONNECTION BOARD SPLIT FOR
ILLUSTRATION PURPOSES
WIRE AS
NEEDED
SYSTEM PUMP
SPEED
CONTROL
BOILER
PUMP
Modbus Instructions
ModBus and BACnet Communication Instructions
17

ModBus and BACnet Communication Instructions
7 Wiring Requirements
Figure 7-2_Control Inputs
GAS PRESSURE SWITCH
DHW THERMOSTAT
ROOM THERMOSTAT /
ZONE CONTROL
FLOW SWITCH
SYSTEM SENSOR
OUTDOOR SENSOR
SEQUENCER / BUILDING
MANAGMENT SYSTEM
LOW VOLTAGE
CONNECTION
BOARD
INLET TEMPERATURE
SENSOR
OUTLET TEMPERATURE /
HI-LIMIT SENSOR
FLUE GAS SENSOR
LOUVER PROVING SWITCH
FLAME SENSOR
LOW WATER CUTOFF
BLOCKED DRAIN SWITCH
DISPLAY PANEL
PC INTERFACE
SMART CONTROL
MODULE
AIR PRESSURE SWITCH
SYSTEM PUMP SPEED CONTROL
MODBUS/BACNET
COMMUNICATION
BOARD
(NO DRAIN SWITCH ON
MODELS WH 55 - 399)
18

7 Wiring Requirements (continued)
Figure 7-3_Control Outputs
LOW VOLTAGE
CONNECTION
BOARD
SMART CONTROL
MODULE
ALARM BELL
LOUVER RELAY
RUN TIME CONTACTS
BUILDING MANAGEMENT
SYSTEM
BOILER PUMP
SYSTEM PUMP
DHW PUMP
IGNITOR
BLOWER
GAS VALVE
DISPLAY PANEL
PC INTERFACE
ModBus and BACnet Communication Instructions
19

20
ModBus and BACnet Communication Instructions
7 Wiring Requirements
Figure 7-4_Control Location_Knight , Knight XL and
Armor
MODBUS / BACNET
COMMUNICATION
BOARD
CONTROL, INTEGRATED
HEAT
EXCHANGER
Figure 7-6_Control Location_Knight/Armor Wall Mount
HEAT EXCHANGER
CONTROL, INTEGRATED
MODBUS / BACNET
COMMUNICATION
BOARD
Figure 7-7_Control Location_Knight Wall Hung
HEAT EXCHANGER
CONTROL,
INTEGRATED
MODBUS / BACNET
COMMUNICATION
BOARD
Figure 7-5_Control Location_Outdoor Knight, Outdoor
Knight XL, Outdoor Armor
CONTROL,
INTEGRATED
MODBUS / BACNET
COMMUNICATION
BOARD
HEAT
EXCHANGER
IMG00568