40
Modbus Interface
Table 9: Input Registers (Read only)
Address
DEC (HEX)
Supported
Commands
Description
Byte: Format
Notes
0 (0x0000)
0x04
Boiler Status
LB: Flag8
Bit: Description
0: PC Manual Mode
1: DHW Mode
2: CH Mode
3: Freeze Protection Mode
4: Flame Present
5: CH(1) Pump
6: DHW Pump
7: System / CH2 Pump
0 = Off, 1 = On
1 (0x0001)
0x04
Lockout Status
MB: Flag8
LB:U8
Bit: Description
1: Lockout Code Type
0 = Automatic Reset Lockout
1 = Manual Reset Lockout
Value = Lockout Code
2 (0x0002)
0x04
Lockout Status
LB:U8
0 = Single / Master Boiler
1 = Slave 1
2 = Slave 2
3 = Slave 3
4 = Slave 4
5 = Slave 5
F = Single / Master Display
768 (0x0300)
0x04
Boiler Supply
Temperature /
System Temperature
S16
Value = 0.1°C
Invalid Value = 32768 (0x8000)
Value is the Boiler Supply
Temperature unless the System
Temperature Sensor is installed
769 (0x0301)
0x04
Boiler Return
Temperature
LB:S8
Value = °C
Invalid Value = 65472 (0xFFC0)
770 (0x0302)
0x04
DHW Storage
Temperature
LB:S8
Value = °C
Invalid Value = 32768 (0x8000)
771 (0x0303)
0x04
Boiler Flue
Temperature
LB:S8
Value = °C
Invalid Value = 65472 (0xFFC0)
772 (0x0304)
0x04
Outdoor Temperature
LB:S8
Value = °C
Invalid Value = 32768 (0x8000)
773 (0x0305)
0x04
Future Use
LB:U8
774 (0x0306)
0x04
Flame Ionization
Current
LB:U8
Value = Flame Current µA
775 (0x0307)
0x04
Boiler / Cascade
Firing Rate
LB:U8
Value = Firing Rate %
776 (0x0308)
0x04
Boiler Setpoint
LB:U8
Value = °C
Invalid Value = 32768 (0x8000)
