SYNC-MODB Rev A
MODBUS COMMUNICATION
INSTRUCTIONS
SYNC Models: 1.0 - 1.3 - 1.5
This manual must only be used by a
qualified heating installer / service
ƽ WARNING
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.
Modbus Instructions
2 Configuration
The Modbus communication board is equipped with a set of ten dip switches that are used to set the board configuration
(address, baud rate, and parity settings). The first eight are used to set the address of each board. The ninth baud rate. The tenth
is parity.
Figure 2-1_Modbus Communication Board
DIP SWITCHES
LED’S
Addressing
The Modbus addressing space is comprised of 256 different Example:
addresss.
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.
•
0 is reserved for broadcast messages from the master
device
1 - 247 are free to use for each unique device
248 - 255 are reserved
•
•
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
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.
In this example:
Address = 0 + 2 + 0 + 0 + 16 + 32 + 0 + 0 = 50
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.
3
Modbus Instructions
2 Configuration
Timing Specifications
Data Transmission Mode
The baud rate for the Modbus board is selectable with Dip
switch #9.
Many Modbus bus master devices can be configured 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 efficient, RTU has been chosen to be used with
all Lochinvar Modbus communication. Please ensure that the
master device is transmitting Modbus RTU.
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.
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.
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>>SETUP>>BMS
buttons. The timeout is adjustable between 5 and 120
seconds. The default timeout is 10 seconds.
Internal Faults:
Normal Operation = 1 second on, 1 second off
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
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.
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.
Parity
Parity is set by the position of Dip switch #10.
0 = No Parity
1 = Odd Parity
If No Parity is selected there will be two stop bits, otherwise
there will be one.
4
Modbus Instructions
2 Configuration
(continued)
Modbus Function Set
Function
Sub Function
Dec
HEX
Description
Dec
HEX
01
1
2
3
4
5
6
7
8
Read Coil Status
Read Input Status
02
03
Read Holding Registers
Read Input Registers
Force Single Coil
04
05
06
Preset Single Register
Read Exception Status
07
08
0
1
2
4
00
01
02
04
Diagnostic - Return Query Data
Diagnostic - Restart Communication
Diagnostic - Return Diagnostic Register
Diagnostic - Force Listen Mode
Diagnostic - Clear Counters and Diagnostic
Registers
10
0A
11
12
13
14
15
16
17
18
20
0B
0C
0D
0E
0F
10
11
Diagnostic - Return Bus Message Count
Diagnostic - Bus Communication Error Count
Diagnostic - Bus Exception Error Count
Diagnostic - Return Slave Message Count
Diagnostic - Return Communication Error Count
Diagnostic - Return Slave NAK Count
Diagnostic - Return Slave Busy Count
Diagnostic - Return Bus Character Overrun Count
Diagnostic - Clear Overrun Counter and Flag
Get Communication Event Counter
Get Communication Event Log
12
14
11
12
15
16
17
23
0B
0C
0F
10
11
Write Multiple Coils
Write Multiple Registers
Report Slave ID
17
Read / Write Multiple Registers
5
Modbus Instructions
2 Configuration
Modbus Exception Codes
MODBUS Exception Codes
Meaning
Code
Name
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.
01
ILLEGAL FUNCTION
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 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.
02
03
ILLEGAL DATA ADDRESS
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.
ILLEGAL DATA VALUE
An unrecoverable error occurred while the server (or slave) was attempting to
perform the requested action.
04
05
SLAVE DEVICE FAILURE
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.
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.
06
08
SLAVE DEVICE BUSY
Specialized use in conjuction 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.
MEMORY PARITY ERROR
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.
0A
GATEWAY PATH UNAVAILABLE
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.
GATEWAY TARGET DEVICE
FAILED TO RESPOND
0B
6
Modbus Instructions
3 Memory Map
Primary Data Tables
Table
Discrete Inputs
Coils
Input Registers
Holding Registers
Data Type
Single Bit
Single Bit
16-Bit Word
16 Bit Word
Read / Write
Read Only
Read / Write
Read Only
Read / Write
SYNC Boiler Memory Map
Coils
Address
00001
00005
Description
Default
Unit
1=ON / 0=OFF
1=ON / 0=OFF
Min. Max. Resolution
Boiler Enable / Room Thermostat 1 / Stage 1
Tank Thermostat
0
0
0
0
1
1
1
1
Discrete Inputs
10001
10002
10003
10004
10005
10006
10007
10008
10009
10010
Manual Reset High Limit 1
Flow Switch 1
0
0
0
0
0
0
0
0
0
0
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Gas Pressure Switch 1
Louver Proving Switch 1
Air Pressure Switch / Flap Valve 1
Blocked Drain Switch 1
Auto Reset High Limit 1
Flame 1
Enable / Room Thermostat 1 / Stage 1
Tank Thermostat
10017
10018
10019
10020
10021
10022
10023
Manual Reset High Limit 2
Flow Switch 2
0
0
0
0
0
0
0
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Gas Pressure Switch 2
Louver Proving Switch 2
Air Pressure Switch / Flap Valve 2
Blocked Drain Switch 2
Flame 2
10033
10034
10035
10036
10038
10039
Run-time Contacts
Alarm Contacts 1
CH Pump 1
DHW Pump 1
Gas Valve 1
0
0
0
0
0
0
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
System Pump
10041
10042
10043
10046
Run-time Contacts 2
Alarm Contacts 2
CH Pump 2
0
0
0
0
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
1=ON / 0=OFF
0
0
0
0
1
1
1
1
1
1
1
1
Gas Valve 2
7
Modbus Instructions
3 Memory Map
SYNC Boiler Memory Map
Input Registers
Address
30001
30002
30003
30004
Description
Discrete Inputs 1 - 16
Discrete Inputs 17 - 32
Discrete Inputs 33 - 48
System / Cascade Setpoint
Default
Unit
NA
NA
NA
Min.
Max. Resolution
0
0
0
0
0
0
0
0
65535
65535
65535
130
1
1
1
Degrees Celsius
0,5
30006
30007
30008
30009
30010
30011
30012
Cascade Total Power
Cascade Current Power
Outlet Setpoint 1
Outlet Temperature 1
Inlet Temperature 1
Flue Temperature 1
Firing Rate 1
0
0
0
0
0
0
0
%
%
100
0
0
800
800
130
130
130
130
100
1
1
Degrees Celsius
Degrees Celsius
Degrees Celsius
Degrees Celsius
%
0,5
0,1
0,1
0,1
1
0
-20
-20
0
30014
30015
30016
30017
30018
30019
30020
30021
Boiler 1 Status Code
Boiler 1 Blocking Code
Boiler 1 Lockout Code
Outlet Setpoint 2
Outlet Temperature 2
Inlet Temperature 2
Flue Temperature 2
Firing Rate 2
0
0
0
0
0
0
0
0
NA
NA
NA
0
0
0
0
0
-20
-20
0
65535
65535
65535
130
130
130
1
1
1
0,5
0,1
0,1
0,1
1
Degrees Celsius
Degrees Celsius
Degrees Celsius
Degrees Celsius
%
130
100
30023
30024
30025
Boiler 2 Status Code
Boiler 2 Blocking Code
Boiler 2 Lockout Code
0
0
0
NA
NA
NA
0
0
0
65535
65535
65535
1
1
1
Holding Registers
40001
40002
Configuration
Coils
0
NA
NA
0
0
65535
65535
1
1
0
0-10 Volt Input / Rate Command /
Setpoint Command
40003
0
%
0
100
1
40004
40005
40006
40007
Tank Setpoint
Tank Temperature
Outdoor Temperature
System Supply Temperature
0
0
0
0
Degrees Celsius
Degrees Celsius
Degrees Celsius
Degrees Celsius
0
87,5
130
60
0,5
0,1
0,1
0,1
-20
-40
-20
130
Configuration Bits
Address 40001 contains configuration 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 configuration 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)
8
Modbus Instructions
4 Wiring Requirements
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. This is required in order to prevent unwanted fluctuations 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 Specification = 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
MOD BUS
CASCADE
9
Modbus Instructions
4 Wiring Requirements
Figure 4-2_Control Inputs
SECONDARY
SMART TOUCH
LOW VOLTAGE
CONNECTION
BOARD
CONTROL MODULE
PRIMARY
SMART TOUCH
CONTROL MODULE
SEQUENCER / BUILDING
MANAGEMENT SYSTEM
OUTDOOR SENSOR
HW TANK SENSOR
SYSTEM SENSOR
HEAT EXCHANGER 1 /
HEAT EXCHANGER 2 INLET
TEMPERATURE SENSOR
HEAT EXCHANGER 1 /
HEAT EXCHANGER 2 OUTLET
TEMPERATURE SENSOR
FLOW SWITCH
BLOCKED DRAIN SWITCH
HEAT EXCHANGER 1 /
HEAT EXCHANGER 2 FLUE GAS SENSOR
HW THERMOSTAT
ROOM THERMOSTAT /
ZONE CONTROL
LOW WATER CUTOFF
TOUCH PANEL
GAS PRESSURE SWITCH
INTERFACE
TOUCH DISPLAY
HEAT EXCHANGER 1 /
HEAT EXCHANGER 2 HIGH LIMIT SENSOR
FLAME SENSOR
MODBUS COMMUNICATION
BOARD
PC INTERFACE
10
Modbus Instructions
4 Wiring Requirements
(continued)
Figure 4-3_Control Outputs
SECONDARY
SMART TOUCH
LOW VOLTAGE
CONNECTION
BOARD
CONTROL MODULE
PRIMARY
SMART TOUCH
CONTROL MODULE
ALARM BELL
RUN TIME CONTACTS
HEAT EXCHANGER 1 /
HEAT EXCHANGER 2
BOILER PUMP
SEQUENCER / BUILDING
MANAGEMENT SYSTEM
SYSTEM PUMP
TOUCH PANEL
HW PUMP
IGNITOR
TOUCH DISPLAY
INTERFACE
PC INTERFACE
BLOWER
GAS VALVE
11
Modbus Instructions
4 Wiring Requirements
Figure 4-4_Control Location
CONTROLLER 2
CONTROLLER 1
MODBUS
COMMUNICATION
BOARD (MTR01)
HEAT EXCHANGER 1
HEAT EXCHANGER 2
Typical Boiler System Wiring
Physical Configuration: Cascade without Individual Monitoring
Modbus RS485 Port on Gateway or Building System
Modbus RS485 Communication Bus
Cascade Daisy Chain Connection
12
Modbus Instructions
4 Wiring Requirements
(continued)
Physical Configuration: Cascade with individual Monitoring
Modbus RS485 Port on Gateway or Building System
Modbus RS485 Communication Bus
Cascade Daisy Chain Connection
Physical Configuration: Direct Control
Modbus RS485 Port on Gateway or Building System
Modbus RS485 Communication Bus
13
Modbus Instructions
5 Unit Operation
Unit Operation with Modbus Communications
To control a SYNC boiler through a Building Management System communicating through Modbus, the SYNC Demand
Configuration must be set to a value of 4, 5, or 6. These configurations allow different control points for a variety of applications.
The configuration can be set by selecting Main>>Setup>>Service/Setup>>Demand Config.
Figure 5-1_Setup Screen
The SYNC 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>>Setup>>BMS>>Modbus Timeout. 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 SYNC boiler through a Building Automation System (BAS), it is very important to ensure that the correct
configuration 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 configuration.
Demand Configuration 4
In this configuration 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 thermostat enable
and tank thermostat enable signal. These signals will be sent to the unit via Modbus.
The holding registers will need to be set as follows:
Holding Registers
Definition
Configuration
Coils
Bit Value (HEX)
Action
40001
00 01
Set Configuration to read 40002
40002
00 01
Enables unit (00 00 disables unit)
NOTE: To ensure proper operation re-send the configuration bits to holding register 40001 prior to issuing a command.
14
Modbus Instructions
5 Unit Operation
(continued)
Demand Configuration 5
In this configuration the unit is controlled by providing an enable signal 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 thermostat enable
and tank thermostat enable signal. These signals will be sent to the unit via Modbus.
The holding registers will need to be set as follows:
Holding Registers
Definition
Configuration
Coils
Bit Value (HEX)
Action
40001
40002
40003
00 05
00 01
00 ##
Set Configuration to read 40002 & 3
Enables unit (00 00 disables unit)
Sets Modulation % or Setpoint
Rate Command
NOTE: To ensure proper operation re-send the configuration 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 Configuration 6
In this configuration the unit is controlled by setting the modulation setpoint from 0 - 100%.
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
Definition
Configuration
Rate Command
Bit Value (HEX)
Action
Set Configuration to read 40003
Sets Modulation %
40001
00 04
40003
00 00
NOTE: To ensure proper operation re-send the configuration 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 SYNC 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.
15
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 SYNC 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
Definition
Configuration
Coils
Bit Value (HEX)
Action
40001
40002
40004
40005
00 4A
00 08
0# ##
0# ##
Set Configuration to read 40002, 4 & 5
Enables Tank Tstat (00 00 disables unit)
Sets Setpoint
Tank Setpoint
Tank Temperature
Passes tank temp from remote sensor
NOTE: To ensure proper operation re-send the configuration 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 SYNC boiler in Cascade with Modbus Monitoring Only
communications, configure the leader boiler per the demand
Any SYNC boiler can be equipped with the Modbus
configurations in this manual. Connect the remaining boilers
communication board and then be set up to operate with its
in the cascade through the normal cascade communications
own internal controls. If necessary, Modbus can be configured
wiring. Cascade control can then be accomplished
as a monitoring device by selecting demand configurations 1 -
automatically through the leader boiler.
3, and polling the Modbus board for the read only variables.
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.
16
Modbus Instructions
5 Unit Operation
(continued)
For Example:
Rate and Temperature Conversions:
Send a setpoint of 110°F.
Rate
The formula to use for the interpolation is:
Rate Command =
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.
(Desired Setpoint – BMS Temp at Low Analog Input) (High
Voltage-Low Voltage) + Low Voltage
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 scientific calculators.
(BMS Temp at High Analog Input – BMS Temp at Low
Analog Input)
From the default values:
For Example:
Desired Setpoint = 110
BMS Temp at Low Analog Input =68
BMS Temp at High Analog=158
High Voltage =10
Rate % HEX
0
20
45
60
80
95
100
00
14
2D
3C
50
5F
64
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.
To send a desired setpoint, the hexadecimal value must be
determined through linear interpolation of programmable
parameters on the BMS Setup Menu:
Temperature
The SYNC boiler passes temperature data in degrees Celsius.
Also, to accommodate decimal places the decimal value must be
divided by 10.
- 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:
Here are the conversions to and from Celsius:
c
f
f
c
T = (5/9) * (T -32)
T = (9/5) * T +32
Example:
DEFAULT
DEFAULT
Outdoor temperature from remote sensor on BAS System = 80°F
VALUES
PARAMETER
80°F = 26.7°C
Deg C Deg F Voltages
Data that needs to be transmitted is 26.7 * 10 = 267
BMS temperature setpoint at
low analog input
21
69.8
2
Decimal
Binary
HEX
10B
267
100001011
BMS temperature setpoint at
high analog input
82
179.6
10
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
1010101011
HEX
2AB
683
17
Modbus Instructions
6 Troubleshooting
Should you encounter problems communicating over
Modbus, the following items should be checked in this order:
Status Codes (Input Registers 30014 and 30023)
2 = Heat Demand blocked due to high absolute outlet
temperature
1. Physical Layer
2. Communications Configuration and Port Settings
3. Modbus Error Codes
3 = Heat Demand blocked due to high absolute flue
temperature
4. Unit Status / Blocking / Lockout Codes
4 = Heat Demand blocked due to high absolute Delta T
(Outlet - Inlet)
Physical Layer
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 no correct communication Cascade
16 = Service function
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
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
Communications
1. Check Dip Switch Configuration of MTR-01 Board
2. Check Baud Rate (9600, 19200)
3. Check Parity
4. Check Slave ID
32764 = Busy with updating status
32765 = DHW blocked due to no present tank sensor
32766 = Burner control(s) manually shut down
32767 = Code not present
5. Check Port Setting on Master, Gateway, and Computers
Modbus Error Codes
1. Check Modbus communication for error codes (see page
6 for Modbus Exception Codes)
2. Check Modbus PDU
Blocking Codes (Input Registers 30015 and 30024)
3. Check Slave ID
4. Check Modbus Command
0 = No blocking _> is divided into sub blockings
1 = SH blocking
5. Check Configuration bits for Holding Register 40001
6. Check Commands and data for Holding Registers
40002 - 40007
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
Unit Status Codes
See Codes in this section
8 = Blocking due to High Flue Temperature
9 = Blocking due to High Outlet Temperature
10 = Service blocking
12 = DHW blocking high outlet temperature (DHW configured
as storage tank)
Boiler Status
The SYNC 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 configuration.
13 = Blocking anti-cycling time
14 = Storage Tank demand Blocked due to Fan problems
15 = No system sensor connected and leader control present
16 = Limit fan speed due to high outlet temperature
17 = Fan min decreased due to low flame current
18 = Limit max fan speed due to high Delta T
19 = Limit max fan speed due to high flue temp
32767 = Code not present
18
Modbus Instructions
6 Troubleshooting
(continued)
1. Turn OFF the main electrical power to the appliance.
2. Turn OFF the main manual gas shutoff to the appliance.
Lockout Codes (Input Registers 30016 and 30025)
161 = EEPROM code Parameters not Re-Programmed by
Lochinvar
3. Unplug the three (3) wire harnesses on the MTR01 control
board (see FIG. 6-1).
164 = EEPROM code No Reset Allowed (> 15 minutes)
166 = EEPROM code Auto Reset High Limit
167 = EEPROM code Blocked Drain
168 = EEPROM code Louver Proving
169 = EEPROM code Gas Pressure Sw
170 = EEPROM code Flow Switch
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.
177 = Sensor 3 short (Flue Sensor)
178 = Sensor 3 open (Flue Sensor)
179 = Sensor 2 short (Inlet Sensor)
6. Replace the four (4) mounting nuts removed in Step 4.
7. Reconnect all three (3) wire harnesses unplugged in Step 3.
180 = Sensor 2 open (Inlet Sensor)
8. Turn on the main electrical power and the main manual gas
shutoff to the appliance.
192 = Sensor 1 short (Outlet Sensor)
193 = Sensor 1 open (Outlet Sensor)
204 = CRC EEPROM failed
205 = EEPROM programmed (display shows “PP”)
206 = EEPROM error in programming
207 = Write error EEPROM
9. Configure the MTR01 control board and unit controls per
this manual and resume operation.
Figure 6-2_Control Panel w/MTR01 Control Board
229 = EEPROM code Watch Dog
230 = EEPROM code fan low (should be high)
231 = EEPROM code fan high (should be low)
232 = EEPROM code no flame when running
233 = EEPROM code no flame after ignition
234 = EEPROM code simultaneous output APS and Fan
235 = EEPROM code APS active not Closed
236 = EEPROM code APS active not Open
237 = EEPROM code flame out of sequence
239 = EEPROM code when gas valve relay test fails
240 = EEPROM code MRHL
UNSCREW THE FOUR (4)
MOUNTING NUTS ON THE MODBUS
CONTROL BOARD (MTR01) AND SET
ASIDE TO SECURE THE
32767 = Code not present
NEW MTR01 CONTROL BOARD
TO THE CONTROL PANEL
Installation / Replacement Procedure
Figure 6-1_MTR01 Control Board
1
UNPLUG THREE (3) WIRE HARNESSES
2
3
19
Modbus Instructions
7 Diagrams
Figure 7-1 Ladder Diagram_Part 1
BOX DEPICTS
OPTIONAL ITEMS
LOW VOLTAGE
120 VAC
HIGH VOLTAGE
CONTROL
MODULE 1
CONTROL
MODULE 2
LOUVER
RELAY 1
X8
X6-8
X5-7
X5-4
X8
X5-7
X5-4
24V
24V
LOUVER
RELAY 2
FLAP
VALVE
AIR PRESSURE
SWITCH
FLAP
VALVE
AIR PRESSURE
SWITCH
X5-14
X5-14
HI-LIMIT
HI-LIMIT
X6-8
X5-8
INLET
SENSOR
INLET
SENSOR
X5-8
X5-1
X5-1
OUTLET
SENSOR
OUTLET
SENSOR
X5-9
X5-2
X5-9
X5-2
FLUE
SENSOR
FLUE
SENSOR
X5-3
X5-3
BLOCKED
DRAIN
AUTO RESET
HIGH LIMIT
AUTO RESET
HIGH LIMIT
X5-10
X5-10
GAS VALVE
GAS VALVE
X2-2
X2-1
X2-2
X2-1
GAS VALVE
RELAY
GAS VALVE
RELAY
BLOWER
1
2
4
5
X5-5
BLOWER
1
2
4
5
X5-5
X5-13
X5-6
X5-13
X5-6
X5-12
X5-12
TR1
TR1
X1-7
X1-7
FLAME ROD
FLAME ROD
SPARK
ROD
SPARK
ROD
CAUTION HIGH VOLTAGE SPARK LEAD
CAUTION HIGH VOLTAGE SPARK LEAD
4
CONTROL
MODULE 1
CONTROL
MODULE 2
CONNECTION BOARD
CN3
X4-3
CN4-3
X4
X4-3
X4-1
X4-2
X4
CN3-16
CN3-15
CN3-14
CN3-13
SHIELD
CN4-1
CN4-2
CN4-4
CN4-6
X4-1
X4-2
X4-4
X4-6
CASCADE
RS485
X4-4
SHIELD
CN3-12
CN3-11
CN3-10
CN3-9
TANK
SENSOR
CN4-5
X4-5
X4-8
X4-7
X4-9
OUTDOOR
SENSOR
CN4-8
CN4-7
CN4-9
CN3-8
SYSTEM
SENSOR
CN3-7
CN3-6
CN3-5
CN3-4
CN3-3
CN3-2
CN3-1
-
EXTERNAL
CONTROL
CN4-10
10VDC
X4-10
+
SHIELD
MOD BUS
RS485
SHIELD
MOD BUS
KIT
NOTES:
1. Where possible, switches are shown without utilities (gas, water or
LADDER DIAGRAM
LBL20058 REV E
electricity) connected to the unit. As such, actual switch states may
vary from those shown on diagrams depending upon whether utilities
are connected or a fault condition is present.
2. See wiring diagram for additional notes.
20
Modbus Instructions
7 Diagrams
(continued)
Figure 7-2 Ladder Diagram_Part 2
BOX DEPICTS
OPTIONAL ITEMS
LOW VOLTAGE
120 VAC
JUNCTION BOX
120VAC
NEUTRAL
GROUND
HIGH VOLTAGE
TERMINAL STRIP
120V SUPPLY "L"
TERMINAL STRIP
120V SUPPLY "N"
JUNCTION BOX
SYSTEM
PUMP
CONTACTS
L1
N / L2
CONTROL MODULE 1
ON / OFF
SWITCH
SYSTEM PUMP
RELAY
F5
5A
X1-2
SYSTEM
PUMP
HEX 1
BOILER
PUMP
SYSTEM PUMP
RELAY
X1-6
X1-8
CONTACTS
HEX 1
BOILER PUMP
RELAY
X1-4
X1-3
BOILER
PUMP
HEX 2
BOILER
PUMP
BOILER PUMP
RELAY
CONTACTS
DHW PUMP
JUNCTION BOX
RELAY
(FIELD SUPPLIED)
JUNCTION
BOX
LOUVER
CONTACTS
BOILER
PUMP
DHW PUMP
RELAY
BLOWER
F4
1
2
X1-1
3.5A
DHW
BLOWER
RELAY
PUMP
3
DHW
PUMP
CONTACTS
F3
1.25A
(FIELD SUPPLIED)
X1-5
X6-8
120 VAC
F2
X5-7
DHW
LWCO
24 VAC
X6-7
X6-2
3.5A
PUMP
J3-2
X6-3
CONTROL
MODULE 1
X6-5
LOW GAS
PRESSURE
SWITCH
HIGH GAS
PRESSURE
SWITCH 1
CONTROL MODULE 2
F5
ON / OFF
SWITCH
CONTROL
MODULE 2
X6-5
X1-2
HIGH GAS
PRESSURE
SWITCH 2
5A
SYSTEM PUMP
RELAY
X1-6
X1-8
HEX 2
BOILER PUMP
RELAY
X1-4
X1-3
BOILER PUMP
RELAY
JUNCTION
BOX
DHW PUMP
RELAY
BLOWER
F4
1
2
X1-1
X6-8
CONTROL
MODULE 1
3.5A
BLOWER
RELAY
3
F3
1.25A
120 VAC
F2
X5-7
X6-10
X6-9
24 VAC
X6-7
X6-2
3.5A
X6-1
X6-6
X3-2
X3-4
X3-1
X3-3
CONNECTION
BOARD
CONNECTION
BOARD
6
5
CN1-4
CONTROL
MODULE 2
CN1-6
LOUVER
PROVING
CN1-12
10
9
CN1-13
CN1-5
HEX 1
FLOW
SWITCH
8
7
CN1-6
CN1-3
X6-10
X6-9
HEX 2
FLOW SWITCH
12
11
13
HW
THERMOSTAT
14
4
X3-2
X3-4
CN1-11
CN1-15
ENABLE
X3-1
X3-3
RUN TIME
CONTACTS
3
1
NOTES:
CN1-10
CN1-7
1. Where possible, switches are shown without utilities (gas, water or
electricity) connected to the unit. As such, actual switch states may
vary from those shown on diagrams depending upon whether utilities
are connected or a fault condition is present.
LWCO
J3-5
J3-6
J3-4
2. See wiring diagram for additional notes.
ALARM
CONTACTS
2
CN1-8
J3-3
TEST SWITCH
PROBE
LADDER DIAGRAM
LBL20046 REV D
21
Modbus Instructions
7 Diagrams
Figure 7-3 Wiring Diagram
LOW VOLTAGE
120 VAC
HIGH VOLTAGE
X3
X5
BOX DEPICTS
OPTIONAL ITEMS
CM 1 PC INTERFACE
JUNCTION
BOX
LOUVER
CONTROL
MODULE 1
CONTACTS
R2
R1
LOUVER
RELAY
PC INTERFACE
X8
BOARD
BR
PR
X1-4
HEX 1
BOILER
PUMP
K1
K2
K3
CONNECTION BOARD
PR
BR
BR
CM 2 PC
CN3
PR
X1-2
CN3-16
INTERFACE
SHIELD
SYSTEM
PUMP
CN4
CN3-15
CASCADE
RS485
X4
OR
OR
CN3-14
CN3-13
CN3-12
CN3-11
CN3-10
HEX 2
SYSTEM
PUMP
SHIELD
Y
X1-3
TANK
SENSOR
HW PUMP
RELAY
GND
GND
ON/OFF SWITCH
BK
W
X1-6
X1-5
L
OUTDOOR
SENSOR
120V SUPPLY
GND
CN3-9
CN3-8
N
GND
SYSTEM
SENSOR
GR
X1-8
X1-1
CN3-7
CN3-6
CN3-5
R
W
G
-
4
CONDUCTORS
EXTERNAL
CONTROL
10VDC
1
2
3
+
CN1
BLOWER
CN3-4
SHIELD
1
2
3
4
5
CN3-3
LOUVER
RELAY 1
CN1-10
MOD BUS
RS485
CN3-2
CN1-2
MOD BUS
KIT
R
X5-5
X5-13
CN3-1
CN1-9
T
SHIELD
FLAP
VALVE
APS
W
X5-6
X5-12
X5-4
X5-10
BK
OR
PK
X6-2
X6-7
GY
BL
AUTO RESET LIMIT
HI-LIMIT
GY
GY
CN1-11
CN2-14
X6-6
PR
PR
ENABLE
X5-7
X5-14
CN2-13
W
W
X6-1
CN1-3
TANK
THERMOSTAT
CN2-12
X5-3
X5-8
PK
CN1-4
BK
RD
INLET
SENSOR
CN2-11
T
BR
MODULE 2
FLOW
SWITCH
CN1-5
CN2-10
CN1-6
T
X5-1
X5-2
X6-9
X6-5
OUTLET
SENSOR
OR
CN2-9
CN1-13
W
Y
FLUE
SENSOR
MODULE
1
OR/BK
CN2-8
X5-9
X6-8
FLOW
CN1-14
X6-10
SWITCH
PK
RD
CN2-7
CN1-12
LOUVER
PROVING
CN2-6
CN1-15
PR
RD
BK
Y
X3-2
X3-4
X2-2
X2-1
GAS
VALVE
RD
CN2-5
CN2-4
CN2-3
CN2-2
CN2-1
CN1-16
RUNTIME
CONTACTS
PR
PR
CN1-8
CN1-7
G
SPARK
ROD
PR
RD
X3-1
X3-3
ALARM
CONTACTS
W/RD
CN1-1
X1-7
FLAME ROD
CN2
BLOCKED
DRAIN
CAUTION HIGH VOLTAGE SPARK LEAD
CONTROL
MODULE 2
X8
PR
BR
X1-2
X1-4
GY
X1-3
X4
W
X1-5
X1-6
LOW GAS
HIGH GAS
BK
PRESSURE SWITCH
PRESSURE
1
GR
RD
X1-8
X1-1
R
W
G
1
2
3
HIGH GAS
PRESSURE
BLOWER
2
1
2
3
4
5
X6-5
LOUVER
RELAY 2
RD
T/BK
W
X5-5
X5-13
T
X6-9
X5-6
X5-12
FLAP VALVE
OR/BK
APS
TEST
SWITCH
OR/BK
X6-10
BK
LOW
J3-1
J3-2
J3-3
J3-4
J3-5
J3-6
OR/BK
GR/BK
PROBE
WATER
CUTOFF
BOARD
BK
X5-4
X5-10
AUTO RESET LIMIT
HI-LIMIT
BL
BL/BK
PR/BK
X5-7
RESET
X5-14
J2-1
J2-2
J2-3
OR
PK
X5-3
X5-8
BK/RD
INLET
SENSOR
RD/BK
W/BK
X5-1
OUTLET
SENSOR
X5-2
X5-9
FLUE
SENSOR
Y/BK
X6-8
PR
BK
Y
X3-2
X3-4
X2-2
X2-1
GAS
VALVE
RD
PR
X3-1
X3-3
G
SPARK
ROD
RD
X1-7
FLAME ROD
RD/W
CAUTION HIGH VOLTAGE SPARK LEAD
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
Notes:
minimum of 105°C. Exceptions: Replacement high voltage 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 problems 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 components for proper connector block locations when using
diagrams to troubleshoot unit.
WIRING DIAGRAM
LBL20045 REV F
22
Notes
23
Revision Notes: Revision A (ECO #C04560) initial release.
SYNC-MODB Rev A
10/09
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