Item value JS transformation error

Setup, Configuration and Use Scripts & Rules
1

Hi,

I’m trying to divide KNX item value by 10:

.items

Number L1_v "L1_V [JS(divide10.js):%.1f] " <energy>  { channel="knx:device:bridge:ZennioKes:L1_v" }

but I’m getting the following error from log:

2019-02-09 12:17:27.902 [WARN ] [rest.core.item.EnrichedItemDTOMapper] - Failed transforming the state '2219.52' on item 'L1_v' with pattern 'JS(divide10.js):%.1f': Cannot format state '2219.52' to format '%.1f'

any ideas what could be wrong?

2

The JS transform will return a string. I wonder if the formatter is clever enough to parse that into a number before trying to format.

Should be able to do the format in your JS

3

not the best news for me as I’m not very strong on coding.
I’m currently using the following JS transformation to convert some of my modbus values:

// Wrap everything in a function (no global variable pollution)
// variable "input" contains data passed by openhab
(function(inputData) {
    // on read: the polled number as string
    // on write: openHAB command as string
    var DIVIDE_BY = 10;
    return parseFloat(inputData) / DIVIDE_BY;
})(input)
4 
(function(inputData) {
    // on read: the polled number as string
    // on write: openHAB command as string
    var DIVIDE_BY = 10;
    var result = parseFloat(inputData) / DIVIDE_BY;
    return result.toString();
})(input)
5

Thanks.
I replaced the code, but I’m getting the same error.

2019-02-09 13:12:16.751 [WARN ] [rest.core.item.EnrichedItemDTOMapper] - Failed transforming the state '2219.52' on item 'L1_v' with pattern 'JS(divide10.js):%.s': Cannot format state '2219.52' to format '%.s'

I tried with “:%.s” as well as it is now string but still.

6

%s no dot required

7

I just noticed and removed that. I don’t get any error now, but it doesn’t convert the value either.

8

Ok let’s try something completely different.
Let’s use a profile:

Number L1_v "L1_V [%.1f] " <energy>  { channel="knx:device:bridge:ZennioKes:L1_v"[profile="transform:JS", function="divide10.js"] }
9

it broke the item altogether

10

What OH version are you running?

11

latest stable 2.4.0

12

without the part [profile=“transform:JS”, function=“divide10.js”] Item reads its old value.
With it, it doesn’t even show up on the bus (log). No errors either.

13

Let’s go back a step.

Can you be clear about whether you’d like to store the divided-by-10 value in the Item ? (rather than just for display in the UI)

As your other (modbus) items are stored that way, it would make sense if this KNX Item was too.
It’s a shame KNX2 doesn’t support transforms as well, but a profile should do a similar job for reading a sensor.

Number L1_v "L1_V [%s] " <energy> { channel="knx:device:bridge:ZennioKes:L1_v"[profile="transform:JS", function="divide10.js"] }

really should work. Be sure you’ve not got any funny quote marks.
Is the KNX channel a number type?

14

Yes, I would like to store the divided-by-10 value, not just to use it the UI.
I don’t see any typos nor funny quote marks.

And the new code still didn’t work.

knx.things:

Thing device ZennioKes [
        address="1.1.8",
        fetch=false,
        pingInterval=900,
        readInterval=0
    ] {
        Type number        : L1_mA        "L1_mA"       [ ga="3/2/1" ]
        Type number        : L2_mA        "L2_mA"       [ ga="3/2/2" ]
        Type number        : L3_mA        "L3_mA"       [ ga="3/2/3" ]
        Type number        : L1_v         "L1_V"        [ ga="3/1/1" ]
        Type number        : L2_v         "L2_V"        [ ga="3/1/2" ]
        Type number        : L3_v         "L3_V"        [ ga="3/1/3" ]
        Type number        : L1_w         "L1_W"        [ ga="3/3/1" ]
        Type number        : L2_w         "L2_W"        [ ga="3/3/2" ]
        Type number        : L3_w         "L3_W"        [ ga="3/3/3" ]

        Type number        : Hz           "Hz"          [ ga="3/0/1" ]

KNX.items

//ZennioKes 1.1.8
Number Hz "Hz [%.1f Hz]" <energy> { channel="knx:device:bridge:ZennioKes:Hz" }

Number L1_mA "L1_mA [%.1f mA]" <energy>  { channel="knx:device:bridge:ZennioKes:L1_mA" }
//Number L1_v "L1_V [JS(divide10.js):%s]" <energy>  { channel="knx:device:bridge:ZennioKes:L1_v" }
//Number L1_v "L1_V [%.1f] " <energy>  { channel="knx:device:bridge:ZennioKes:L1_v" }
//Number L1_v "L1_V [%s] " <energy> { channel="knx:device:bridge:ZennioKes:L1_v" [profile="transform:JS", function="divide10.js"] }
Number L1_v "L1_V [%s]" <energy> { channel="knx:device:bridge:ZennioKes:L1_v"[profile="transform:JS", function="divide10.js"] }
Number L1_w "L1_W [%.1f W]" <gauge>  { channel="knx:device:bridge:ZennioKes:L1_w" }

Number L2_mA "L2_mA [%.1f mA]" <energy> { channel="knx:device:bridge:ZennioKes:L2_mA" }
Number L2_v "L2_V [%.1f mV]" <energy> { channel="knx:device:bridge:ZennioKes:L2_v" }
Number L2_w "Töökoja elekter [%.1f W]" <gauge> { channel="knx:device:bridge:ZennioKes:L2_w" }

Number L3_mA "L3_mA [%.1f mA]" <energy> { channel="knx:device:bridge:ZennioKes:L3_mA" }
Number L3_v "L3_V [%.1f mV]" <energy> { channel="knx:device:bridge:ZennioKes:L3_v" }
Number L3_w "Serveri elekter [%.1f W]" <gauge> { channel="knx:device:bridge:ZennioKes:L3_w" }

so it is a number type…

15

up!

16

I think you have run into the same problem as here