--------------------------------------------------------------------------------
 ModbusTCP registers for Hx5xx (H4531, H0530, H3531, H3530, H7531, H7530, H4531R,
                                H3531R, H7531R, H5524, H6520, H5521, H6521, H3536)

 standard ModbusTCP port: 502

 v1.2 for firmware 9-5-0-2 or higher, 2024-07-11
 ModbusTCP specification is free available: http://modbus.org/specs.php
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List of Supported Modbus commands
--------------------------------------------------------------------------------

|--------------------------------|--------|------------------------------------|
| Command                        | Code   | Description                        |
|                                | [HEX]  |                                    |
|--------------------------------|--------|------------------------------------|
| Read Holding Register(s)       | 0x03   | Reads 16 bit register(s)           |
|--------------------------------|--------|------------------------------------|
| Write Single Register(s)       | 0x06   | Write one 16 bit register          |
|--------------------------------|--------|------------------------------------|
| Write Multiple Register(s)     | 0x10   | Write 16 bit register(s)           |
|--------------------------------|--------|------------------------------------|


Measured values (read only registers)
--------------------------------------------------------------------------------

|-----------------------|--------|--------|--------|---------------------------|
| Variable              | Reg.Nr.| Reg.Nr.| Type*) | Description               |
|                       | [HEX]  | [DEC]  |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| temperature           | 0x0031 | 49     | Int*10 | unit [C] or [F]         |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| reletive humidity     | 0x0032 | 50     | Int*10 | unit [%RH]                |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| computed value (CV)   | 0x0033 | 51     | Int*10 | units depends on computed |
|                       |        |        |        | value **)                 |
|-----------------------|--------|--------|--------|---------------------------|
| atmospheric pressure  | 0x0034 | 52     | Int*X  | units depends on selected |
| or                    |        |        |        | pressure units or device  |
| CO2 level (P/CO2)     |        |        |        | type ***)                 |
|-----------------------|--------|--------|--------|---------------------------|
|-----------------------|--------|--------|--------|---------------------------|
| dew point temperature | 0x0036 | 54     | Int*10 | unit [C] or [F]         |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| absolute humidity     | 0x0037 | 55     | Int*10 | unit [g/m^3]              |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| Specific humidity     | 0x0038 | 56     | Int*10 | unit [g/kg]               |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| mixing ratio          | 0x0039 | 57     | Int*10 | unit [g/kg]               |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| specific enthalpy     | 0x003A | 58     | Int*10 | unit [kJ/kg]              |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| humidex in C         | 0x0060 | 96     | Int*10 | unit [C]                 |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| humidex in F         | 0x0061 | 97     | Int*10 | unit [F]                 |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
|-----------------------|--------|--------|--------|---------------------------|
| relay 1 state         | 0x003B | 59     | Int1   | 0 - open, 1 - closed      |
|-----------------------|--------|--------|--------|---------------------------|
| relay 2 state         | 0x003C | 60     | Int1   | 0 - open, 1 - closed      |
|-----------------------|--------|--------|--------|---------------------------|
| binary input 1 state  | 0x003D | 61     | Int1   | 0 - low, 1 - high         |
|-----------------------|--------|--------|--------|---------------------------|
| binary input 2 state  | 0x003E | 62     | Int1   | 0 - low, 1 - high         |
|-----------------------|--------|--------|--------|---------------------------|
| binary input 3 state  | 0x003F | 63     | Int1   | 0 - low, 1 - high         |
|-----------------------|--------|--------|--------|---------------------------|


Control registers (read/write registers) 
--------------------------------------------------------------------------------

|-----------------------|--------|--------|--------|---------------------------|
| Variable              | Reg.Nr.| Reg.Nr.| Type*) | Description               |
|                       | [HEX]  | [DEC]  |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| relay 1 far control   | 0x0042 | 66     | Int2   | 0 - controlled by device  |
|                       |        |        |        | 1 - set relay to close    |
|                       |        |        |        | 2 - set relay to open     |
|-----------------------|--------|--------|--------|---------------------------|
| relay 2 far control   | 0x0043 | 67     | Int2   | 0 - controlled by device  |
|                       |        |        |        | 1 - set relay to close    |
|                       |        |        |        | 2 - set relay to open     |
|-----------------------|--------|--------|--------|---------------------------|
| remote acoustic mute  | 0x005B | 91     | Int2   | write 0 to mute acoustic  |
|                       |        |        |        |                           |
|-----------------------|--------|--------|--------|---------------------------|


Device identification (read only registers)
--------------------------------------------------------------------------------

|-----------------------|--------|--------|--------|---------------------------|
| Variable              | Reg.Nr.| Reg.Nr.| Type*) | Description               |
|                       | [HEX]  | [DEC]  |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| serial number high    | 0x1035 | 4149   | BCD    | unique serial number have |
| serial number low     | 0x1036 | 4150   | BCD    | 8 digits                  |
|-----------------------|--------|--------|--------|---------------------------|
| device type           | 0x1037 | 4151   | HEX    |                           |
|-----------------------|--------|--------|--------|---------------------------|


Alarm status and limits (read only registers)
--------------------------------------------------------------------------------

|-----------------------|--------|--------|--------|---------------------------|
| Variable              | Reg.Nr.| Reg.Nr.| Type*) | Description               |
|                       | [HEX]  | [DEC]  |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| temp. alarm1 state    | 0x5001 | 20481  | Int1   | 0 - none, 1 - active      |
| humidity alarm1 state | 0x5002 | 20482  | Int1   | 0 - none, 1 - active      |
| CV alarm1 state       | 0x5003 | 20483  | Int1   | 0 - none, 1 - active      |
| P/CO2 alarm1 state    | 0x5004 | 20484  | Int1   | 0 - none, 1 - active      |
| temp. alarm2 state    | 0x5005 | 20485  | Int1   | 0 - none, 1 - active      |
| humidity alarm2 state | 0x5006 | 20486  | Int1   | 0 - none, 1 - active      |
| CV alarm2 state       | 0x5007 | 20487  | Int1   | 0 - none, 1 - active      |
| P/CO2 alarm2 state    | 0x5008 | 20488  | Int1   | 0 - none, 1 - active      |
| alarm on bin input 1  | 0x5009 | 20489  | Int1   | 0 - none, 1 - active      |
| alarm on bin input 2  | 0x500A | 20490  | Int1   | 0 - none, 1 - active      |
| alarm on bin input 3  | 0x500B | 20491  | Int1   | 0 - none, 1 - active      |
|-----------------------|--------|--------|--------|---------------------------|
| alarm settings        | 0x500C | 20492  |        | registers are described   |
|                       |   ..   |   ..   |        | in the user manual        |
|                       | 0x502B | 20523  |        |                           |
|-----------------------|--------|--------|--------|---------------------------|
| bin alarm settings    | 0x502C | 20524  |        | registers are described   |
|                       |   ..   |   ..   |        | in the user manual        |
|                       | 0x5031 | 20529  |        |                           |
|-----------------------|--------|--------|--------|---------------------------|


Notice
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 In table are stated numbers of the Modbus registers (Reg.Nr). Address of 
 Modbus register is minus one than register number (e.g. register with number 
 0x0031 have the Modbus address 0x0030). Inside Modbus TCP frames are physically
 send address.

*)  Type:
     
    BCD ...... register is in BCD format (16bit)
    HEX ...... number in HEX format (16bit)
    Int1 ..... register is in range 0 to 1 (16bit)
    Int2 ..... register is in range 0 to 2 (16bit)
    Int*10 ... register is in format integer*10 (16bit); 125=12.5C;
               error1=9999, error2=-9999, n/a=-9998
    Int*X .... register format depends on value type; error2=-9999, n/a=-9998
               Atmospheric pressure ***):
                   hPa ...... integer*10;   9760  = 976.0hPa
                   PSI ...... integer*1000; 14156 = 14.156PSI
                   inHg ..... integer*100;  2882  = 28.82inHg
                   mBar ..... integer*10;   9761  = 976.1mBar
                   oz/in2 ... integer*10;   2265  = 226.5oz/in2
                   mmHg ..... integer*10;   7321  = 732.1mmHg
                   inH2O .... integer*10;   3919  = 391.9inH2O
                   kPa ...... integer*100;  9761  = 97.61kPa
               CO2 level:
                   ppm ...... integer;      897   = 897ppm

**) Supported Computed values:

    Dew point temperature ... C or F
    Absolute humidity ....... g/m^3
    Specific humidity ....... g/kg
    Mixing ratio ............ g/kg
    Specific enthalpy ....... kJ/kg
    Humidex in C ........... C

