Boiler Parameter Worksheet
Appendix
56
ENVI
®
CONTROLS: WRITE-ONLY MODBUS
®
REGISTERS
It is important to note that the ENVI
®
controls require the user to write two values simultaneously to a single register.
For example, if the operator wants the CH Setpoint to be 140°F and the DHW Setpoint to be 180°F and the user
follows the 40011 procedure below, the decimal value to be written is (35840 + 184 = 36024). Refer to the M-104
MODBUS Calculator.xls spreadsheet to help with these calculations.
MODBUS
®
WRITE-ONLY REGISTER MAP
40011
– CH Setpoint & DHW Setpoint
40013
– Boiler Operation & High Outdoor Air Temperature
40015
– Minimum Outdoor Air Setpoint & Low Outdoor Air Temperature
CH Setpoint
°F
+
10
-
32
1.8
512
(Integer)
+
DHW Setpoint
°F
+
10
-
32
1.8
2
(Integer)
Min OA
Setpoint °F
+
10
-
32
1.8
512
(Integer)
+
+
40
-
32
1.8
2
(Integer)
Low OA
Temperature °F
256
+
High Outdoor Air
Temperature °F
+
40
-
32
1.8
2
(Integer)
Boiler Operation
(0, 1, 2 or 3)
