- • Simple thermostat with hysteresis
- • Simple Heating management using Weekly schedule and Presence switch
- • Heating and Cooling modes
- • Power limiting
- • Notification on high temperature
- • 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
- • Editing multiple devices
- • Integrate multiple Core control units
- • Safe values
- • How to combine two daily schedules in one day
- • Grouping or linking devices together
- • Access control
- • Using statistic values in Smart Rules
- • Hot water circulation pump control
- • Integrate multiple Cores
- • Dimmer limits
- • 2020.1
- • 2020.1*
- • 2019.1
- • 2018.1
- • 2017.1 - Charts updated
- • 2017.1 - Blinds automation - Depth of sun rays
- • 2017.1 - Blinds automation - angle control update
- • 2017.1 - Replace module action
- • 2017.1 - Expose devices
- • 2017.1 – Daily schedule Smart Rule
- • 2017.1 - Permissions
- • 2017.1 - Double click and triple click
- • 2017.1 - Set to Automatic mode - "Push buttons event" Smart Rule
- • 2017.1 - Multi-value switch
- • 2017.1 - Core update from the app
- • Firmware changelog
TapHome Bus over 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 neccessary but nice to have, in case there is unexpected problem with noise |
Bus topology | Daisy chain, Tree | Daisy chain is optimal for long distances, tree can be used up to 600m, and star is also acceptable. |
Termination resistor | 100 Ohm | In most cases, communication works well even without termination resistor, but is much more prone to noise. |
Max number of modules | < 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
Average packet size … 40 bytes => 3ms
Round robin duration for 90 modules … 270ms
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