RE: Connecting Askoma Askoheat+ using the Modbus binding

1

Hi Community

Thank you Konfusius for sharing this information. I tried to get the values of the following registers:

> Register	Description			Datatype
> 108		Emergency Mode		1 word / byte / 0 = off, 255 = on	
> 109		status				1 word / uint16
> 110		heaterload			1 word / uint16 / 250-30000 watt
> 325+326	temperature s0		2 words / float32 / floating point °celcius	
> 510		legiotemp			1 word / byte / 50-65
> 612+613	relay1count			2 words / int32 / 0-100.000
> 614+615	relay2count			2 words / int32 / 0-100.000
> 616+617	relay3count			2 words / int32 / 0-100.000
> 618+619	relay4count			2 words / int32 / 0-100.000
> 620+621	relay5count			2 words / int32 / 0-100.000	
> 627		legiostatus			1 word / byte
> 629		legiopasttime		2 words / array[4][5.17] / dd:hh:mm
> 631		Errorstatus			1 word / uint16

I think I understand the data type byte, uint16, int32.
I don’t understand float32 (register 325+326). I get the values 0x41b1 and 0x7a02 which is 16’817 and 31’234 in decimal. How do I calculate the temperature (22.18) from these two values?

{325} MODBUS_EMA_TEMPERATURE_FLOAT_SENSOR0 = 0x41b1 → 22.18
{326} = 0x7a02

Can somebody explain how to get the value of register 628+629 to dd:hh:mm?

{628} MODBUS_VAL_LEGIO_PAST_TIME = 0x000c → 12d 12h 39m
{629} = 0x0c27

Any help would be much appreciated.

BR Thomas

2

check this

You need to look in the bits of the registers and get the number.
But sometimes the sequence of the bytes can be swapped

3

After reading more about the modbus binding I figured out how to do it.
Part of the Things file:

    Bridge poller asko_ema "EMA" [ start=325, length=2, refresh=10000, type="input" ]
    {
        Thing data wassertemp "Wassertemperatur" [ readStart="325", readValueType="float32" ]
    }

Part of the Items file:

Number    Wassertemperatur    "Wassertemperatur"      <energy>    {channel="modbus:data:askomatcp:asko_ema:wassertemp:number"}

This works fine.

4

Register 628 is defined as array according to the Askoma documentation:

grafik
grafik1376×147 11.4 KB

But I think the modbus binding does no provide a proper item type.

5

Register 628 (last legionella protection) needs a transformation. I created this script:

openhabian@openhab3:/etc/openhab/transform $ cat float2date.js
(function(inp) {
    // input: the polled number as float
    // output: string
//  let log = require('openhab').log('my_logger');
//  log.info("f2di in: " + inp);
    var MperH = 60;             // minutes per hour
    var MperD = MperH * 24;     // minutes per day
    inp = inp * 100000000000000000000000000000000000000000;
    inp = MperD * inp;          // total minutes
    inp = Math.round(inp)       // make integer
    var Days = Math.floor(inp / MperD);
    var rest = inp % MperD;
    var Hours = Math.floor(rest / MperH);
    var Minutes = rest % MperH;
    Hours = ("0" + Hours).slice (-2);
    Minutes = ("0" + Minutes).slice (-2);
    var Output = Days + ":" + Hours + ":" + Minutes + " (D:H:M)";
//  log.info("f2d out: " + Output);
    return Output;
})(input)

The transformation script must be added to the thing:

Thing data AskLegio "Heizstab Letzter Legionellenschutz" [ readStart="628", readValueType="float32", readTransform="JS(float2date.js)" ]

And the item is a string type item:

String AskLegio "Heizstab Letzter Legionellenschutz"  {channel="modbus:data:askomatcp:AskInput3:AskLegio:string"}

The sitemap looks like this:

grafik

But for whatever reason it’s not very accurate. This is shown by the Askome web UI:

grafik

But I think it’s accurate enough.

Good luck
Reinhold