IO-Link Sensors convert from hex to decimal

brot123 · January 18, 2024, 3:21pm

Hello, I have an IO-Link pressure transmitter from Wika which I read out via an IFM IO-Link master using Rest. The value comes in hexadecimal format e.g. 0B64, I first have to convert this value into a binary number
this results in 0000101101100100 binary,

As 14 bits remain for the pressure measurement, the last two zeros would be omitted from the binary value 0000101101100100. If I convert this value into decimal I get the value 729, this value is my pressure value (this value would then have to be shifted 2 places to the left with the decimal point)

What is the best way to create a template sensor?
this is my Rest sensor:

- sensor:
      - name: iolinknew
        value_template: "{{ states('sensor.iolink') | int(base=16) | bin }}"
        unit_of_measurement: "Binary"

Does not work.HA indicates in the logs

Invalid config for ‘template’ at configuration.yaml, line 285: required key ‘state’ not provided Invalid config for ‘template’ at configuration.yaml, line 286: ‘value_template’ is an invalid option for ‘template’, check: sensor->0->value_template

this is my rest sensor

  - platform: rest
    name: iolink
    resource: http://192.168.1.124/00-02-01-71-85 47/iolinkmaster/port[1]/iolinkdevice/pdin/getdata
    value_template: "{{ value_json.data.value }}"
    scan_interval: 10

i look after a good soloution to get the data ,thanks alot

123 · January 18, 2024, 3:29pm

Replace value_template with state.

  - sensor:
      - name: iolinknew
        state: "{{ states('sensor.iolink') | int(base=16) | bin }}"

There are two configuration methods for creating Template entities: modern and legacy. Your configuration is mostly modern format except for value_template which is legacy format. You can’t mix the two formats.

I also suggest you initially remove the unit_of_measurement option. After you have confirmed the configuration works (i.e. no error message and the sensor is created), add the option to the sensor’s configuration and confirm it still works.

tom_l · January 18, 2024, 10:20pm

Also once you get the template working as you want you can just use it in the rest sensor value_template. There’s no need for a separate template sensor, unless you need the hexadecimal value as well.

brot123 · January 19, 2024, 4:36pm

Thanks for your help, I have just tested again, I got a value from the rest sensor 068C was the value, the iolinknew sensor gives me 1676 back what says if I divide this value by 4 then I come to the pressure value 419 this would then have to shift the decimal places by 2 to the left, then I would have the value!

If I can get the value 419 directly from the rest sensor then that would be very good.I love keep it simple
Unfortunately I’m a zero at coding so I’ll be honest…thank you very much

123 · January 19, 2024, 5:24pm

Use this in the REST sensor and then you don’t need the Template Sensor.

    value_template: "{{ (value_json.data.value | int(base=16)) / 400 }}"

Calculation tested in the Template Editor:

brot123 · January 26, 2024, 5:52pm

Thank you all Guys! This works perfect

brot123 · April 19, 2024, 10:11am

Hello again, I had the unique opportunity to get a high-quality volume flow meter from Endress+Hauser (Picomag) at a reasonable price. It is already integrated in Iolink, so I need help once again, so my well project is finished.
The flow meter outputs a 32-bit floating point number via IEEE754 (single precision). As with the pressure sensor above, I obtain the data via the second Iolink port via Rest, I then have the following data format I have taken it apart for better readability 3F000000459018664120000000C801

3F000000= conductivity of the water 45901866 = Totalizer 412000000 = Volumeflow 00C8 = process temperature 01= Device status

the values are in this order, conductivity and temperature and status I do not necessarily need, only totalizer and volume flow.
how can i best convert the required bytes as i want to omit parts in this example?
thank you very much!

Troon · April 19, 2024, 10:12am

{% from 'ieee754.jinja' import ieee754_float %}
{% set x = "3F000000459018664120000000C801" %}
Conductivity:  {{ x[0:8] }} = {{ ieee754_float(x[0:8]) }}
Totalizer:     {{ x[8:16] }} = {{ ieee754_float(x[8:16]) }}
Volume flow:   {{ x[16:24] }} = {{ ieee754_float(x[16:24]) }}
Process temp:  {{ x[24:28] }}     = {{ x[24:28]|int(base=16)/10 }}
Device status: {{ x[28:30] }}       = {{ x[28:30]|int(base=16) }}

brot123 · April 19, 2024, 10:41am

thanks @troon , I have installed the jinja extension and now it shows me the way you have it. how can I now process the values as individual entities, sorry for the question how do I now get the connection to the template that I get current values?

Troon · April 19, 2024, 10:46am

If you have the full hex string that I called x as sensor.x, then set up a template sensor for each.

State template for totalizer (replace sensor.x with your actual entity ID):

{% from 'ieee754.jinja' import ieee754_float %}
{{ ieee754_float(states('sensor.x')[8:16]) }}

with unit of measurement set to L and device class to volume.

and for volume flow:

{% from 'ieee754.jinja' import ieee754_float %}
{{ ieee754_float(states('sensor.x')[16:24]) }}

with unit of measurement set to L/s. There is a volume_flow_rate device class, but the docs don’t list L/s as an allowable unit. You could do this (converting the string macro output to a number with float before multiplying by 60):

{% from 'ieee754.jinja' import ieee754_float %}
{{ ieee754_float(states('sensor.x')[16:24])|float(0)*60 }}

and set the unit to L/min and device class to volume_flow_rate.

brot123 · April 19, 2024, 11:32am

I have also done this step, unfortunately there seems to be no data coming in, I have a simulation running via the iolink program so that I can change “dry” values. but the REST sensor is updated every 10 seconds in HA from this side no problem. with the volume flow I also got this error (I took the customized template) or should I rather create them individually as yaml?

Troon · April 19, 2024, 11:39am

OK, so your existing sensor has a string representing a data structure as its state, with the long hex value as one of the elements of that structure.

So first create a template sensor called “iolink value” or something like that, with state template:

{{ (states('sensor.iolink_2')|from_json)['data']['value'] }}

No unit or device class. That should have a state of 3F000... — then use that sensor in the templates above in place of sensor.iolink_2.

Alternatively, you could do it in one step:

{% from 'ieee754.jinja' import ieee754_float %}
{{ ieee754_float((states('sensor.iolink_2')|from_json)['data']['value'][8:16]) }}

brot123 · April 19, 2024, 12:23pm

I have revised the initial rest sensor so that only the HEX numbers arrive, the totalizer value now comes in converted:) unfortunately the volume flow is still unknown

  - platform: rest
    name: iolink
    resource: http://192.168.1.124/00-02-01-71-85-47/iolinkmaster/port[2]/iolinkdevice/pdin/getdata
    unique_id: endress_iolink_picomag
    scan_interval: 10
    value_template: "{{ value_json.data.value }}"

brot123 · April 19, 2024, 12:39pm

OMG, it works:) Thank you alot @Troon

Troon · April 19, 2024, 12:41pm

My stupid mistake. Macros always return strings and need converting before doing arithmetic on them.

For litres per minute you need:

{% from 'ieee754.jinja' import ieee754_float %}
{{ ieee754_float(states('sensor.iolink_2')[16:24])|float(0)*60 }}

Fixed in my post above also.

That’s what the NoneNoneNone... in your screenshot was all about: your prior sensor wasn’t an IEEE754 string so my macro was returning None, then the template was “multiplying” that None sixty times…