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Domain Sensors
Nick Berardi edited this page Jul 19, 2026
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| Value | Meaning |
|---|---|
| 0 | No error |
| 1 | Out of range low |
| 2 | Out of range high |
| 3 | Not installed (5.2 only — in 5.1 the guide marks value 3 as Reserved) |
| 4 | Open / error open |
| 5 | Short / error short |
| Value | Meaning |
|---|---|
| 0 | No error |
| 3 | Not installed |
| 4 | Error |
| COS | No |
| Access | R |
| Data length | 16 bytes |
Full array of installed sensor status/value pairs for monitoring. Prefer 5.2 Controlling Sensors for the sensors that actually control the thermostat.
| Field | Byte | Values |
|---|---|---|
| Built in Temperature Sensor Status | Byte 0 | 0: No Error 1: Out of Range Low 2: Out of Range High 3: Reserved 4: Open 5: Short 6-255 Reserved |
| Built In Temperature Sensor Value | Byte 1 | bits 7: Built-in Sensor Sign 0: Positive 1: Reserved bits 6: Built-in Sensor ½ Celsius Indicator 0: “.0” Celsius 1: “.5” Celsius bits 5-0: Built-in Sensor value in Celsius 0-40: Value (refer to appendix 1 for C / F conversion) 40-63: Reserved (out of range) |
| Wired Remote Temperature Sensor Status | Byte 2 | 0: No Error 1: Out of Range Low 2: Out of Range High 3: Reserved 4: Open 5: Short 6-255 Reserved |
| Wired Remote Temperature Sensor Value | Byte 3 | bits 7: Wired Remote Sensor Sign 0: Positive 1: Reserved bits 6: Wired Sensor ½ Celsius Indicator 0: “.0” Celsius 1: “.5” Celsius bits 5-0: Built-in Sensor value in Celsius 0-40: Value (refer to appendix 1 for C / F conversion) 41: Reserved 42-63: Reserved (out of range) |
| Wired Outdoor Temperature Sensor Status | Byte 4 | 0: No Error 1: Out of Range Low 2: Out of Range High 3: Reserved 4: Open 5: Short 6-255 Reserved Note: This status is for wired and wireless sensor values only |
| Wired Outdoor Temperature Sensor Value | Byte 5 | bits 7 Outdoor Sensor Sign 0: Positive 1: Negative bits 6 Outdoor Sensor ½ Celsius Indicator 0: “.0” Celsius 1: “.5” Celsius bits 5-0: Outdoor Sensor Value 0-55: Value (refer to appendix 1 for C / F conversion) 56-63 : Reserved (out of range) Note: This value is for wired and wireless sensor values only |
| Built in Humidity Sensor Status (except 8810) | Byte 6 | 0: No Error 1: Reserved 2: Reserved 3: Not Installed 4: Error 5-255: Reserved |
| Built in Humidity Sensor Value (except 8810) | Byte 7 | 0: Reserved 1-99: %RH 100-255: Reserved |
| RAT Sensor Status (except 8810,8820) | Byte 8 | 0: No Error 1: Out of Range Low 2: Out of Range High 3: Reserved 4: Open 5: Short 6-255 Reserved |
| RAT Sensor Value (except 8810,8820) | Byte 9 | bits 7 RAT Sensor 0: Positive 1: Negative bits 6 Outdoor Sensor ½ Celsius Indicator 0: “.0” Celsius 1: “.5” Celsius bits 5-0: Outdoor Sensor Value 0-55: Value (refer to appendix 1 for C / F conversion) 56-63 : Reserved (out of range) |
| LAT Sensor Status (except 8810,8820) | Byte 10 | 0: No Error 1: Out of Range Low 2: Out of Range High 3: Reserved 4: Open 5: Short 6-255 Reserved |
| LAT Sensor Value (except 8810,8820) | Byte 11 | bits 7 LAT Sensor 0: Positive 1: Negative bits 6 Outdoor Sensor ½ Celsius Indicator 0: “.0” Celsius 1: “.5” Celsius bits 5-0: Outdoor Sensor Value 0-55: Value (refer to appendix 1 for C / F conversion) 56-63 : Reserved (out of range) |
| Wireless Outdoor Temperature Sensor Status (except 8810,8820) | Byte 12 | 0: No Error 1: Out of Range Low 2: Out of Range High 3: Reserved 4: Open 5: Short 6-255 Reserved Note: This status is for wired and wireless sensor values only |
| Wireless Outdoor Temperature Sensor Value (except 8810,8820) | Byte 13 | bits 7 Outdoor Sensor Sign 0: Positive 1: Negative bits 6 Outdoor Sensor ½ Celsius Indicator 0: “.0” Celsius 1: “.5” Celsius bits 5-0: Outdoor Sensor Value 0-55: Value (refer to appendix 1 for C / F conversion) 56-63 : Reserved (out of range) Note: This value is for wired and wireless sensor values only |
| Wireless Outdoor Humidity Sensor Status (except 8810,8820) | Byte 14 | 0: No Error 1: Reserved 2: Reserved 3: Not Installed 4: Error 5-255: Reserved |
| Wireless Outdoor Humidity Sensor Value (except 8810,8820) | Byte 15 | 0: Reserved 1-99: %RH 100-255: Reserved |
Temperature values use the packed Celsius byte (see Temperature Encoding). Humidity values are percent RH.
Guide typo: Byte 1 lists "0-40: Value 40-63: Reserved" — overlapping at 40; presumed intent is 41–63 reserved (Byte 3 states 41+ reserved for the same encoding). See Guide Errata.
| COS | Yes |
| Access | R |
| Data length | 8 bytes |
The sensors actually selected for indoor/outdoor temperature and humidity control.
| Byte | Field |
|---|---|
| 0 | Indoor temperature status |
| 1 | Indoor temperature value (packed °C) |
| 2 | Outdoor temperature status |
| 3 | Outdoor temperature value |
| 4 | Indoor humidity status |
| 5 | Indoor humidity % |
| 6 | Outdoor humidity status |
| 7 | Outdoor humidity % |
COS causes: controlling sensor status or value changes.
| COS | Yes |
| Access | R |
| Data length | 8 bytes |
| Read selector | Module index as Read Request data: 0–3 = Support Module 1–4 |
| Models | Except 8810; up to 4 modules (8081 temp / 8082 temp+RH) |
| Field | Byte | Values |
|---|---|---|
| Module Address | Byte 0 | 0: Reserved 1:1 2:2 3:3 4:4 5-255: Reserved |
| Sensor 1 Status | Byte 1 | 0: Normal 1-2: Reserved 3: Not Installed 4: Error 3-255: Reserved |
| Sensor 1 Mode | Byte 2 | 0: Control 1: Monitor 2: Absent 3-255: Reserved |
| Sensor 1 Temp Value | Byte 3 | bits 7: Sensor 1 Temp 0: Positive 1: Reserved bits 6: Wired Sensor ½ Celsius Indicator 0: “.0” Celsius 1: “.5” Celsius bits 5-0: Built-in Sensor value in Celsius 0-40: Value (refer to appendix 1 for C / F conversion) 41-63: Reserved (out of range) |
| Sensor 2 Status | Byte 4 | 0: Normal 1-2: Reserved 3: Not Installed 4: Error 3-255: Reserved |
| Sensor 2 Mode | Byte 5 | 0: Control 1: Monitor 2: Absent 3-255: Reserved |
| Sensor 2 Temp Value | Byte 6 | bits 7: Sensor 2 Temp 0: Positive 1: Reserved bits 6: Wired Sensor ½ Celsius Indicator 0: “.0” Celsius 1: “.5” Celsius bits 5-0: Built-in Sensor value in Celsius 0-40: Value (refer to appendix 1 for C / F conversion) 41-63: Reserved (out of range) |
| Sensor 2 RH Value | Byte 7 | 0: Reserved 1-99: %RH 100-255: Reserved |
Modules can be configured as Control, Monitor, or Absent. Controlling module counts also appear in Setup / Installer Settings.
| COS | Yes (status → Timed Out) |
| Access | R/W |
| Data length | 2 bytes |
| Constraint | For Automation outdoor-sensor mode only |
| Byte | Field | Notes |
|---|---|---|
| 0 | Outdoor sensor status | Read/COS only. 0 No error; 4 Timed Out. Writes must send 0 (does not overwrite real status). |
| 1 | Temperature | Packed °C. Writes do not generate COS. Negatives limited per guide. |
Staleness: if no successful update for 10 minutes, value is invalid / timed out. Host should refresh more often than every 10 minutes when sharing one outdoor sensor across multiple thermostats.
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