homeassistant

15783 readers

21 users here now

Home Assistant is open source home automation that puts local control and privacy first.
Powered by a worldwide community of tinkerers and DIY enthusiasts.

Home Assistant can be self-installed on ProxMox, Raspberry Pi, or even purchased pre-installed: Home Assistant: Installation

Discussion of Home-Assistant adjacent topics is absolutely fine, within reason.
If you're not sure, DM @GreatAlbatross@feddit.uk

founded 2 years ago

MODERATORS

GreatAlbatross@feddit.uk

greatalbatross@lemmy.world

Modbus problem (lemmy.world)

submitted 4 weeks ago by peregus@lemmy.world to c/homeassistant@lemmy.world

2 comments fedilink hide all child comments

In the office we have an automation system that talks in modbus. Right now I have Node Red that receives data from modbus (via IP), sends it to MQTT and send messages from MQTT to modbus. In HA I have 15 MQTT climates that works. I want to bypass Node Red; I've added an automation that gets triggered when a MQTT values arrives and sends the new value to mobus:

alias: Climate_update_modbus_setpoint_studio1
description: ""
triggers:
  - trigger: mqtt
    topic: home_assistant/thermostat/setpoint/Studio1
actions:
  - data:
      hub: picnet
      address: 1099
      value: "{{ (trigger.payload | float * 10) | int }}"
    action: modbus.write_register
mode: queued

The problem is that the modbus change takes a lot.

I change the climate setpoint, after about 0.5 seconds the MQTT value changes and the automation gets triggered
the modbus register changes in a range of about 0.5-3 seconds
sometimes the automation gets triggered and I see the trigger bar yellow instead of blue and the modbus register changes after longer

With Node Red I have no problem with modbus. What can I check to try to find the source of the problem?

you are viewing a single comment's thread
view the rest of the comments

[–] chaospatterns@lemmy.world 1 points 3 weeks ago

Sorry, I don't fully understand your setup or the problem.

Seems like it's modbus <--> node-red <--> MQTT <--> HASS?

But you want to cut out node red? So if the input to MQTT is slow, what's writing that MQTT value?

Without having any more context, I think I'd reach for Wireshark/tcpdump and just see the packets come in and understand timing.