Universal Wall-Mount Controller
Modbus Communication Module User Guide
www.neptronic.com
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Holding Registers Table
Table Glossary
Name
Description
Name
Description
W
Writable Register
ASCII
For registers containing ASCII (8-bit) characters
RO
Read Only Register
MSB
Most Significant Byte
Unsigned
For range of values from 0 to 65,535, unless otherwise specified
LSB
Least Significant Byte
Signed
For range of values from -32,768 to 32,767, unless otherwise specified
MSW
Most Significant Word
Bit String
For registers with multiple values using bit mask (example, flags)
LSW
Least Significant Word
Holding Register Table
Register
Index
Description
Data Type
Range
Writable
4000
0
Address - Neptronic ID and Modbus address of current
device.
Unsigned
MSB = 22, LSB = 1-246
W
4000
1
MSTP Baud Rate.
Unsigned
Scale 100
0, 9600, 19200, 38400, or 57600, 0 = Auto Baud Rate Detection
Value/100 (e.g. 38400 baud = 384)
W
4000
2
Communication port configuration.
Unsigned
1 = No parity, 2 Stop bits, 2 = Even parity, 1 stop bit, 3 = Odd parity, 1 stop bit
W
4000
3
ProdName_87, characters 8-7 of 8 name characters.
ASCII
MSB = 84 (T), LSB = 85 (U)
W
4000
4
ProdName_65, characters 6-5 of 8 name characters.
ASCII
MSB = 67 (C), LSB = 66 (B)
W
4000
5
ProdName_43, characters 4-3 of 8 name characters.
ASCII
MSB = 50 (2), LSB = 52 (4)
W
4000
6
ProdName_21, characters 2-1 of 8 name characters.
ASCII
MSB = 32 (Space), LSB = 0 (Null)
W
4000
7
Controller Product_Version, actual firmware version.
Unsigned
1 to 65535 (e.g. 115)
RO
4000
8
Controller parameters version.
Unsigned
1 to 65535 (e.g. 102)
RO
4000
9
System Status 1.
Bit String
[B1, B5, B7
– B15]
:
Reserved
B0: System operation
0 = Normal, 1 = Fault
B2: System override by NSB or OCC
0 = Normal, 1 = OFF
B3:
ChangeOverMode
0 = Cooling, 1 = Heating
B4:
AL_FlowSwitch
0 = No alarm, 1 = Alarm activated
B6:
AL_DirtyFilter
0 = No alarm, 1 = Alarm activated
RO
