@mschaeffler/node-red-thermostat 0.4.0
A Node Red node to control an (electric) heater
@mschaeffler/node-red-thermostat
A Node Red node to control an (electric) heater.
Install
$ npm install @mschaeffler/node-red-thermostat
Closed Loop Control
A heating device that just can be switched on and off, can be closed loop controlled:
The on / off cycles are done like this:
The on time is calculated in this way:
with this values
| value | description |
|---|---|
| t_on | time of on cycle |
| T_nom | nominal Temperature, parameter nominal |
| T_act | actual temperature, msg.payload.temperature |
| s | minimal Delta, parameter summand |
| f_cycle | $1.4$ for the 1st cycle, $1.2$ for the 2nd, then $1$ |
| f_msg | control coefficient, msg.payload.factor |
| f_node | control coefficient, parameter factor |
| t_cycle | time of complete cycle, parameter cycleTime |
Input
| msg. | type | description |
|---|---|---|
| payload | object | data to control the thermostat |
There are two different ways to control the thermostat:
direct control
msg.payload is a destinct value:
| msg.payload | type | description |
|---|---|---|
true |
boolean | starts heating according to already set data |
false |
boolean | stops heating |
on |
string | starts heating according to already set data |
off |
string | stops heating |
1 |
number | sets the cycle count to 1 and starts heating |
2 |
number | sets the cycle count to 2 and starts heating |
3 |
number | sets the cycle count to 3 and starts heating |
4 |
number | sets the cycle count to 4 and starts heating |
5 |
number | sets the cycle count to 5 and starts heating |
0 |
number | stops heating |
control with objects
msg.payload is an object with at least one of these members:
| msg.payload. | type | description |
|---|---|---|
| temperature | number | actual temperature for the closed loop control |
| block | boolean | blocks the heating (e.G. open window) |
| nominal | number | nominal temperature |
| factor | number | multilies the control coefficent (parameter factor) with this value |
| cycleTime | number | sets the cyclic time |
| cycleCount | number | sets the nuber of cycles |
Outputs
state feedback
This is the general feedback: heating is on or off.
| msg. | type | description |
|---|---|---|
| topic | string | parameter topic |
| payload | value according to parameter feedback |
control output
This controls the heater according to the cycles.
| msg. | type | description |
|---|---|---|
| topic | string | parameter topic |
| payload | boolean | control value to switch the heater |
Parameters
| config | type | description |
|---|---|---|
| topic | string | topic value for the output messages |
| nominal | number | nominal temperature for the closed loop control |
| minDelta | number | actual temp must be by this value lower then the nominal to start heating |
| summand | number | additional summand for the closed loop control |
| factor | number | control coefficient for the closed loop control |
| cycleTime | number | time period of one heating cycle |
| cycleCount | number | number of heating cycles |
| feedback | string | style of the state feedback |
feedback formats
There are four formats for the state feedback:
| feedback type | description |
|---|---|
| Boolean | boolean value |
| "on" / "off" | strings "on" or "off" |
| 1 / 0 | numbers 1 or 0 |
| cycle count | numbers cycleCount or 0 |
Example Flow
Author
License
LGPL-2.1
