Lochinvar Armor 101 Series User manual

100305786_2000558371_Rev B
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
Armor Models: 1250 - 4000
Series: 100 & 101

2
1 Introduction
e information contained in this manual provides general guidelines for the implementation of ModBus and BACnet
communication with the Lochinvar Armor.
All ModBus networks are implemented utilizing a master-slave arrangement where all Armors are slaves and the master is a
building automation system capable of communicating over a RS-485 serial connection. BACnet networks are implemented
using a token passing protocol (MS/TP) where multiple masters and slaves share a common RS-485 bus. e Lochinvar BACnet
interface is a master only.
Contents
1. INTRODUCTION
Definitions .................................................................... 2
Minimum System Requirements.................................. 2
2. INSTALLATION
Definitions .................................................................... 2
3. MODBUS CONFIGURATION
Addressing................................................................... 3
Timing Specifications................................................... 4
Parity............................................................................ 4
Data Transmission Mode............................................. 4
ModBus Board Diagnostics ......................................... 4
Internal Faults......................................................... 4
ModBus Function Set............................................. 5
ModBus Exception Codes ........................................... 6
4. MODBUS MEMORY MAP
Primary Data Tables.................................................... . 7
Memory Map................................................................ 7-8
Input Registers ....................................................... . 8
Holding Registers................................................... . 8
Configuration Bits ........................................................ . 8
5. BACNET CONFIGURATION
Addressing................................................................... ..9
Timing Specifications................................................... 10
Communication Board Diagnostics ............................. 10
Internal Faults.......................................................... 10
6. BACNET MEMORY MAP
Primary Data Tables.................................................... .11
Appliance Map..........................................................11-12
Input Registers ............................................................ .12
Holding Registers................................................... .12
7. WIRING REQUIREMENTS
Physical Wiring ............................................................ .13
Typical System Wiring ............................................ 16-17
8. UNIT OPERATION
Unit Operation with ModBus Communications...... 18-21
9. TROUBLESHOOTING........................................... 22-24
Revision Notes ................................................... Back Cover
Abbreviation or Acronym Meaning
ASCII American Standard Code for Information Interchange
BACnet A data communication protocol for Building Automation 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
Definitions
Minimum System Requirements
• BAS system or computer with a serial or USB port with a converter to RS-485. • Shielded twisted pair communication
cable.

3
ModBus and BACnet Instructions
2 ModBus Configuration
Addressing
e ModBus addressing space is comprised of 256 dierent
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.
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 used to set the
baud rate. e tenth is used to set the parity.
LED’S
DIP SWITCHES
Figure 2-1_ModBus Communication Board

4
2 ModBus Configuration
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 tank temperature and/or 0-10V BMS voltage is
provided by the BAS to the unit, it is critical that the values
be updated every few seconds. If the unit 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 by accessing parameter H6
(see the Armor Service Manual for instructions for setting
parameters). 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 unit (such as providing an enable command),
the BAS must refresh these commands at least every 4
minutes. If the commands are not refreshed, the unit 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 5 and 6 of this manual.
ModBus and BACnet Instructions

5
ModBus and BACnet Instructions
2 ModBus Configuration (continued)
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

6
2 ModBus Configuration
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
ModBus and BACnet Instructions

7
ModBus and BACnet Instructions
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 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
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 Enable 0 1=ON / 0=OFF 0 1 1
10010 Tank Thermostat 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
10036 DHW Pump 0 1=ON / 0=OFF 0 1 1
10038 Gas Valve 0 1=ON / 0=OFF 0 1 1
10039 Recirculation Pump 0 1=ON / 0=OFF 0 1 1
10049 Blower Power 0 1=ON / 0=OFF 0 1 1
3 ModBus Memory Map

8
Input Registers
Address Description Default Unit Min. Max. Resolution
30001 Discrete Inputs 1 - 16 0 N/A 0 65535 1
30002 Discrete Inputs 17 - 32 0 N/A 0 65535 1
30003 Discrete Inputs 33 - 48 0 N/A 0 65535 1
30004 System / Cascade Setpoint 0 Degrees Celsius 0 130 0,5
30006 Cascade Total Power 0 % 100 800 1
30007 Cascade Current Power 0 % 0 800 1
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
30014 Status Code 0 N/A 0 65535 1
30015 Blocking Code 0 N/A 0 65535 1
30016 Lockout Code 0 N/A 0 65535 1
30026 Discrete Inputs 49 - 64 0 N/A 0 65535 1
30027 Lockout Code Leader 0 N/A 0 65535 1
30028 Lockout Code Member 1 0 N/A 0 65535 1
30029 Lockout Code Member 2 0 N/A 0 65535 1
30030 Lockout Code Member 3 0 N/A 0 65535 1
30031 Lockout Code Member 4 0 N/A 0 65535 1
30032 Lockout Code Member 5 0 N/A 0 65535 1
30033 Lockout Code Member 6 0 N/A 0 65535 1
30034 Lockout Code Member 7 0 N/A 0 65535 1
Holding Registers
40001 Configuration 0 N/A 0 65535 1
40002 Coils 0 N/A 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
Memory Map
3 ModBus Memory Map
Configuration Bits
Address 40001 contains conguration bits sent from the BAS to the unit. ese bits tell the unit to use its own internal inputs,
or inputs from the BAS. When a bit is set to 1, the unit 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 3: Tank Setpoint
Bit 6: Tank Temperature
Bit 8 - 15: Not Used (Default = 0)
Bit 0 (LSB): Enable
Bit 1: Tank ermostat
Bit 2: Rate Command / 10 - 10V Input / Setpoint Command
ModBus and BACnet Instructions

9
ModBus and BACnet Instructions
4 BACnet Configuration
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.
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 640000. Using the above example, the
Device Instance will be:
Device Instance = 640000 + 50 = 640050
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 4-1_Communication Board
Since the BACnet communication board is a master device, address 127 is the highest address that can be used.

10
4 BACnet Configuration
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.
Switch #9 Switch#10 Baud Rate
OFF OFF 9600
ON OFF 19200
OFF ON 38400
ON ON 76800
When the tank temperature and/or 0-10V BMS voltage is
provided by the BAS to the appliance, it is critical that the
values be updated every few seconds. If the appliance 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 by accessing
parameter H6 (see the Armor Service Manual for instructions
for setting parameters). 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 appliance (such as providing an enable
command), the BAS must refresh these commands at least
every 4 minutes. If the commands are not refreshed, the
appliance will revert to operating based on its own inputs.
ModBus and BACnet Instructions

11
ModBus and BACnet Instructions
5 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
Enable BV 0 none 0 1 1
Tank Thermostat BV 4 none 0 1 1
Binary Inputs
Manual Reset High Limit BI 0 none 0 1 1
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
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
Enable BI 8 none 0 1 1
Tank Thermostat BI 9 none 0 1 1
Run Time Contacts BI 32 none 0 1 1
Alarm Contacts BI 33 none 0 1 1
DHW Pump BI 35 none 0 1 1
Gas Valve BI 37 none 0 1 1
Recirculation Pump BI 38 none 0 1 1
Power Fan BI 48 none 0 1 1

12
5 BACnet Memory Map
Object Name Object
Type
Object
Instance Units Min Max Resolution
Inputs
Binary Inputs 0-15 AI 0 none 0 65535 1
Binary Inputs 16-31 AI 1 none 0 65535 1
Binary Inputs 32-47 AI 2 none 0 65535 1
System / Cascade Setpoint AI 3 Deg. C 0 130 0.5
Cascade Total Power AI 5 Percent 100 800 1
Cascade Current Power AI 6 Percent 0 800 1
Outlet Temperature AI 8 Deg C 0 130 0,1
Inlet Temperature AI 9 Deg C -20 130 0,1
Flue Temperature AI 10 Deg C -20 130 0,1
Firing Rate AI 11 Percent 0 100 1
Status Code AI 13 none 0 65535 1
Blocking Code AI 14 none 0 65535 1
Lockout Code AI 15 none 0 65535 1
Binary Inputs 48-63 AI 25 none 0 65535 1
Lock-Out Error Leader AI 26 none 0 1 1
Lock-Out Error Member 1 AI 27 none 0 1 1
Lock-Out Error Member 2 AI 28 none 0 1 1
Lock-Out Error Member 3 AI 29 none 0 1 1
Lock-Out Error Member 4 AI 30 none 0 1 1
Lock-Out Error Member 5 AI 31 none 0 1 1
Lock-Out Error Member 6 AI 32 none 0 1 1
Lock-Out Error Member 7 AI 33 none 0 1 1
Analog Values
Configuration AI 0 none 0 65535 1
Coils AI 1 none 0 65535 1
0-10 Volt Input / Rate Command / Setpoint Command AI 2 Percent 0 100 1
Tank Setpoint AI 3 Deg C 0 87,5 0,5
Tank Temperature AI 4 Deg C -20 130 0,1
Memory Map (continued)
ModBus and BACnet Instructions

13
ModBus and BACnet Instructions
6 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.
Note that when the Tank Temperature is provided by the BAS,
it needs to be refreshed every few seconds. is is required
in order to prevent unwanted uctuations in temperature. If
these values are not provided every few seconds (timeout is
programmable), the appliance will revert to its own internal
control. If this temperature is provided by the BAS, but any
of the other control signals are being provided, the BAS will
still need to refresh this input at least every 4 minutes.
Physical Wiring
Figure 7-1_Terminal Strip Connections
TANK SENSOR
DIR #2000549759 00

14
6 Wiring Requirements
Figure 6-2_Control Inputs
ModBus and BACnet Instructions
GAS PRESSURE SWITCHES
TANK THERMOSTAT /
SENSOR
ENABLING DEVICE
SEQUENCER / BUILDING
MANAGEMENT SYSTEM
LOW VOLTAGE
CONNECTION
BOARD
INLET TEMPERATURE
SENSOR
OUTLET TEMPERATURE /
HI-LIMIT SENSOR
FLUE GAS SENSOR
LOUVER PROVING SWITCH
FLAME SENSOR
FLOW SWITCH
BLOCKED DRAIN SWITCH
DISPLAY PANEL PC INTERFACE
SMART CONTROL
MODULE
ARMOR
BAS BOARD
DIS
PLAY P
A
NEL
DIR #2000549760 00

15
ModBus and BACnet Instructions
6 Wiring Requirements (continued)
Figure 6-3_Control Outputs
LOW VOLTAGE
CONNECTION
BOARD
SMART CONTROL
MODULE
ALARM CONTACTS
LOUVER RELAY
RUN TIME CONTACTS
SEQUENCER / BUILDING
MANAGEMENT SYSTEM
RECIRCULATION SYSTEM PUMP
CONTACTOR (FIELD SUPPLIED)
APPLIANCE PUMP
CONTACTOR (FIELD SUPPLIED)
IGNITOR
BLOWER
GAS VALVE
APPLIANCE RATE OUTPUT
DISPLAY PANEL
PC INTERFACE
120V
SUPPLYSYSTEMPU MP BOILER PUMP DHW PUMP
MAX. 1.5 AMPSPER CONNECTION
NL FIELDSUPPLIED CONTACTO R MUST
BE INSTALLED
LINE VOLTAGE
TERMINAL
STRIP
D
I
S
DIR #2000549763 00

16
6 Wiring Requirements
Figure 6-4_Control Location
DIR #2000555139 00
Typical System Wiring
DIR #2000555143 00
Cascade Daisy Chain Connection
BACnet or Modbus RS485 Communication Bus
BACnet or Modbus RS485 Port on Gateway or Building System
Physical Configuration: Cascade without Individual Monitoring
ModBus and BACnet Instructions

17
ModBus and BACnet Instructions
6 Wiring Requirements (continued)
DIR #2000555143 00
BACnet or Modbus RS485 Communication Bus
BACnet or Modbus RS485 Port on Gateway or Building System
Physical Configuration: Direct Control
DIR #2000555143 00
Cascade Daisy Chain Connection
BACnet or Modbus RS485 Communication Bus
BACnet or Modbus RS485 Port on Gateway or Building System
Physical Configuration: Cascade with Individual Monitoring

18
7 Unit Operation
Unit Operation with ModBus or BACnet Communications
A Building Automation System (BAS) can monitor the Armor without the need to change the default conguration of the
SMART SYSTEM control. When the BAS is to provide commands or values to the control, parameter H5 ModBus must be set
to Active (reference the Armor Service Manual for the procedure on how to set parameters).
e SMART SYSTEM control is equipped with two (2) communication timers. e rst is used whenever the control receives
the tank temperature through ModBus or BACnet. ese values need to be updated on a regular basis to prevent unwanted
temperature variations. is timer is programmable from 1 to 255 seconds. It is Lochinvar’s recommendation that this timer
be set as short as possible. is timeout can be adjusted by accessing parameter H6 ModBus Time. e timer is reset with the
ModBus Time setting every time the temperatures are updated. e second timer is used for all other commands and values
provided through ModBus or BACnet. It has a xed timeout of four (4) minutes. If either of these timers expire before the next
update, the SMART SYSTEM control will revert to using its local inputs.
When a BAS is to control a Armor, the installer must congure the SMART SYSTEM control to receive commands and data
through ModBus or BACnet. ere are several dierent control methods available, as described in this section. ese methods
are determined by the settings in four (4) dierent parameters.
Demand Configuration: ENABLE = ACTIVE; BMS = INACTIVE
In this conguration the unit is controlled by setting the setpoints locally on the unit and providing an enable signal through
ModBus or BACnet communications.
All sensors and limiting devices should be hardwired to the terminal strip on the back of the unit excluding the enable signal.
is signal will be sent to the unit via ModBus or BACnet.
e holding objects or registers will need to be set as follows:
Object Holding Registers Definition Bit Value (HEX) Action
AV0 40001 Conguration 00 01 Set Conguration to read 40002
AV1 40002 Coils 00 01 Enables unit (00 00 disables unit)
NOTE: To ensure proper operation re-send the conguration bits to holding register 40001 or Object AV0 prior to issuing a
command.
ModBus and BACnet Instructions

19
ModBus and BACnet Instructions
7 Unit Operation (continued)
Demand Configuration: ENABLE = INACTIVE; BMS = ACTIVE
In this conguration the unit is controlled by setting the modulation setpoint from 0 - 100%, or the setpoint. e 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.
is signal will be sent to the unit via ModBus or BACnet.
e holding registers will need to be set as follows:
For proper hexadecimal conversion of rate percentage, please refer to the Rate and Temperature Conversion section on page 17
of this manual.
Demand Configuration: ENABLE = ACTIVE; BMS = ACTIVE
In this conguration the unit is controlled by providing an enable signal. e setpoint command will be determined by the
parameters in the control and a rate command through ModBus or BACnet communications.
e 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. ese signals will be sent to the unit via ModBus or BACnet.
e holding objects or registers will need to be set as follows:
For proper hexadecimal conversion of rate percentage, please refer to the Rate and Temperature Conversion section on page 17
of this manual.
NOTE: To ensure proper operation re-send the conguration bits to holding register 40001 or Object AV0 prior to issuing a
command.
Object Holding Registers Definition Bit Value (HEX) Action
AV0 40001 Conguration 00 05 Set Conguration to read 40002 & 3
AV1 40002 Coils 00 01 Enables unit (00 00 disables unit)
AV2 40003 Rate Command 00 ## Sets Modulation % or Setpoint
NOTE: To ensure proper operation re-send the conguration bits to holding register 40001 or Object AV0 prior to issuing a
command.
Object Holding Registers Definition Bit Value (HEX) Action
AV0 40001 Conguration 00 04 Set Conguration to read 40003
AV2 40003 Rate Command 00 00 Sets Modulation % or Setpoint

20
7 Unit Operation
Cascade
In order to operate the Armor in Cascade with ModBus
or BACnet communications, congure the leader unit per
the demand congurations in this manual. Connect the
remaining units in the cascade through the normal cascade
communications wiring. Cascade control can then be
accomplished automatically through the leader unit.
Please note that with ModBus or BACnet communication
connected to only the leader unit, 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 communication board.
However, each unit can be monitored without the need to
control each one individually.
Monitoring Only
Armors that are equipped with the ModBus or BACnet
communication board can be set up to operate with their own
internal controls. If necessary, ModBus or BACnet can be
congured as a monitoring device by polling the communication
board for the read only variables.
ModBus and BACnet Instructions