- • Requirements for the controlled devices
- • Simple thermostat with hysteresis
- • Simple Heating management using Weekly schedule and Presence switch
- • Power limiting
- • Notification on high temperature (DEPRECATED)
- • Configuring hysteresis control via Equation Smart Rule
- • PID Temperature regulation
- • PID Cascade
- • Regulation of Boiler Cascade
- • Equithermic regulation
- • Heating control in high electricity tariff via load management tariff indicator input
- • Boiler and pump control
- • Heating and Cooling modes
- • Editing multiple devices
- • Integrate multiple control units Core
- • Safe values
- • How to combine two daily schedules in one day
- • Grouping or linking devices together
- • Using statistic values in Smart Rules
- • Hot water circulation pump control
- • Exporting data from TapHome into Google Spreadsheet using Integromat
- • Exporting device descriptions
- • 2022.1
- • 2021.3
- • 2021.2
- • 2021.1
- • 2020.1
- • 2019.1
- • 2017.1 - Blinds automation - angle control update
- • 2017.1 - Blinds automation - Depth of sun rays
- • 2017.1 - Charts updated
- • 2017.1 - Core update from the app
- • 2017.1 - Double click and triple click
- • 2017.1 - Expose devices
- • 2017.1 - Multi-value switch
- • 2017.1 - Permissions
- • 2017.1 - Replace module action
- • 2017.1 - Set to Automatic mode - "Push buttons event" Smart Rule
- • 2017.1 – Daily schedule Smart Rule
- • Firmware changelog
- Documentation
- Network architecture
- TapHome Bus (RS485)
TapHome Bus (RS485)
TapHome modules communicate via proprietary protocol, over RS485 physical layer.
The basic principle is to provide collision-free reliable and prompt communication between central control unit and modules.
RS485 physical layer
Bus connections must be powered by the same potential, because there is neither galvanic, nor optical isolation. While RS485 is based on voltage difference between A and B wires, it provides high protection from noise even on long twisted pair of wires.
Core provides 3 bus connections. Maximum number of modules on each bus is 30. Altogether 90 modules on one control unit.
Topology and wiring
Parameter | Recommended | Note |
|---|---|---|
Cable length | < 600m | Up to 1200m in special conditions. |
Cable type | AWG 20 - 22, Twisted pair | Shielding is usually not necessary, but it is advisable to have it if data line interference caused by induced voltage occurs. |
Change to Topology view in ETS project: | Daisy chain, Tree | Daisy chain is optimal for long distances, tree can be used up to 600m, and star is also acceptable. Ring topology is prohibited. |
Termination resistor (between A and B wires) | 100 Ohm at the most distant point of the bus | In most cases, communication works well even without termination resistor, but is much more prone to noise. |
Max number of modules (connected on 1 bus) | < 32 | In good conditions (minimum noise, short wire distance, daisy chain topology), there can be up to 100 modules connected on 1 bus. |
TapHome Bus protocol
TapHome Bus protocol is based on round robin principle, where Core is master, and all connected modules are acting as slaves. In standard operation, module can only send response to a query. This provides a few benefits:
*Collision-free communication
*Similar performance regardless of number of changes that are being transmitted
*Immediate error detection
Communication parameters
Round robin
doc_tap_avg_ size_duration;
Packet structure
*Start byte (0xAA)
*Packet length
*Broadcast / unicast
*Source address
*Destination address
*Action: Module-specific actions / Universal actions (Get Status, Get Description, Get general configuration, Get Uptime, Can broadcast, Identify LED)
*Checksum
Baud rate … 115200 bps
Parity … None
Start bit … 1
Stop bit … 1
Data bits … 8