Modbus Math Statement

Configuration
1

Hello Everyone. I was wondering if someone could help me finish this code. Im a little stuck. I need to write a value to a modbus register on my home battery system I have built. Postive number tell it to charge and negative numers to discharge. Problem is I cannot write negative numbers easily. Positive number are fine no issue. I have to write my values via the 2 compliment method. The scale is 0-32768 are postive and 65536 - 32768 are negative numbers. For example if I wish for my battery to discharge by -100W its 65536 - 100 = 65436 = -100.

All I want my statement to say. If the houseload is between 0 and 3000W then write that value to the template output as positive numbers are not an issue. However IF the house load is between -1 to -3000W then 65536 + (-house load). If its anything else the write + 40W. This the code I have so far.

  • platform: template
    sensors:
    grid_step:
    friendly_name: “Grid Setpoint to Battery”
    value_template: >-
    {% if states(‘house load’) | float > 0 and states(‘house load’) | float < 3000 %}
    {{states(’???’) | int}}
    {% elif states(‘house load’) | float > -1 and states(‘house load’) | float < -3000 %}
    {{ 65536 + states(’-???’) | int}}
    {% else %}
    40
    {% endif %}

I think im on the right track but im a novice and writing code.

Any help would be much appreciated.

Thanks

Gareth

2

did you find a solution to this? I am facing same issue
#modbus_n00b

3

Yes. However there were some issues. Can you tell me what you are trying to achieve?

Is yours for a controlling charge/discharge of an inverter?

4

This was the code I was using. Hope it helps

- platform: template

sensors:

mode_3:

friendly_name: “Inverter Control”

value_template: >-

{% if states(‘sensor.invertersetpoint’) | float >= 0 and states(‘invertersetpoint’) | float <= 1000 %}

{{states(‘sensor.invertersetpoint’) | int}}

{% elif states(‘invertersetpoint’) | float <= -10 and states(‘invertersetpoint’) | float >= -1000 %}

{{ (float(states(‘invertersetpoint’))) | round + (65536) }}

{% else %}

0

{% endif %}