Thermal Solutions APEX APX425C Installation, Operating And Service Instructions page 110

10
Operation
(continued)
4. Modbus Register List
A list of available Modbus registers and descriptions is stored in the display and provided in Table 10-26. To access
Select to access the list of available Modbus registers.
Table 10-26: Modbus Register List
Modbus Protocol
Register Name
Central Heat
400577
Enable/Disable
400563 LLCH Modbus Stat
400203 Burner on/off
400006 Demand source
400066 CH heat demand
400083 DHW heat demand
Low Temperature
400123
Loop heat demand
CH Modbus
410579
Setpoint
CH Sequencer
410562
Modbus Setpoint
410211 CH setpoint
410453 DHW setpoint
410546 Lead Lag setpoint
410212 CH TOD setpoint
110
ENABLE/DISABLE
Central Heat Enable/Disable
0 = Disable
1 = Enable
When this register is not written every "Modbus Command Time Out" parameter
seconds (default 30 seconds), CH Modbus Stat is reverted to 0 no demand.
LL CH Modbus STAT
0 = no demand
1 = demand
When this register is not written every "Modbus Command Time Out" parameter
seconds (default 30 seconds), CH Modbus Stat is reverted to 0 no demand.
Burner On/Off burner.
1 = on
0 = off
0 = Unknown
1 = No source demand
2 = Central heat
3 = Domestic hot water
4 = Lead Lag slave
5 = Lead Lag master
6 = Central heat frost protection
7 = Domestic hot water frost protection
8 = No demand due to burner switch turned off
9 = Domestic hot water storage
11 = Warm weather shutdown
0=Off,
1=On
0=Off,
1=On
0=Off,
1=On
SETPOINTS
Use this register to change the boiler setpoint.
When this register is not written every "Modbus Command Time Out" parameter
seconds (default 30 seconds), setpoint reverts to local setpoint
valid range 60°F to 190°F
Use this register to change the multiple boiler Sequencer setpoint.
When this register is not written every "Modbus Command Time Out" parameter
seconds (default 30 seconds), setpoint reverts to local setpoint
valid range 60°F to 190°F
Status of local setpoint
Status of local setpoint
Status of local setpoint
Status of local setpoint
APEX Installation, Operating, & Service Instructions
Description
Read (R) /
Write (W)
W
W
R
R
R
R
R
W
W
R
R
R
R
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