XATO — Temperature Thresholds

Configures alarm thresholds for OneWire temperature sensors. When a sensor temperature exceeds the threshold, signal F21 is triggered.

Formats

Query a Threshold

>QXATO{IDX}<

Response:

• >RXATO{IDX}{TAG}{SIGN}{VALUE}< — Threshold is configured
• >RXATO{IDX}U< — No threshold defined for this index

Field	Format	Description
IDX	Single digit (0–9)	Threshold slot
TAG	Letter (A–J)	Sensor tag
SIGN	+ or -	Greater-than (+) or less-than (-)
VALUE	4 digits	Temperature in tenths (e.g., 0100 = 10.0°C)

Set a Threshold

>SXATO{IDX}1{TAG}{SIGN}{VALUE}<

Response: Command accepted (threshold saved)

Field	Format	Description
IDX	Single digit (0–9)	Threshold slot (10 available)
TAG	Letter (A–J)	Sensor tag to monitor
SIGN	+ or -	Condition: + = exceeds, - = drops below
VALUE	4 digits	Temperature threshold in tenths of °C

Delete a Threshold

>SXATO{IDX}U<

Response: Command accepted (threshold removed)

Examples

Query threshold slot 0:

>QXATO0<
>RXATO0A+0850<   ← Threshold set: Tag A > 85.0°C

Query empty slot:

>QXATO5<
>RXATO5U<   ← Slot 5 has no threshold

Set threshold: Tag A > 85.0°C (engine overtemp alarm):

>SXATO01A+0850<
>SXATO01A+0850<   ← Confirmed

Set threshold: Tag C < 5.0°C (cargo freezing alarm):

>SXATO21C-0050<
>SXATO21C-0050<   ← Confirmed

Delete threshold slot 3:

>SXATO3U<

Threshold Slots

Slot	Index
0–9	10 independent thresholds available

Each slot monitors a specific sensor tag and condition independently.

Temperature Conditions

Greater-Than (+)

Triggers signal F21 when sensor temperature exceeds the threshold.

Example: Overheat alarm

>SXATO01A+0900<   ← Alert if tag A > 90.0°C

Less-Than (-)

Triggers signal F21 when sensor temperature drops below the threshold.

Example: Freezing alarm

>SXATO21C-0000<   ← Alert if tag C < 0.0°C

Temperature Value Format

4-digit representation in tenths of degrees Celsius:

Value	Temperature
0850	85.0°C
1000	100.0°C
0000	0.0°C
-010	-1.0°C

Signal Generated

Signal F21 — Temperature threshold exceeded

Use this signal in event definitions:

>SED00NA0;F21+<   ← Report when threshold is crossed

Workflow

1. Tag sensors — Use XATL to assign tags (A–J)
2. Configure thresholds — Use >SXATO{IDX}1{TAG}{SIGN}{VALUE}<
3. Create events — Use >SED00NA0;F21+< to report threshold violations
4. Monitor — Query thresholds with >QXATO{IDX}<

Complete Example

Setup: Monitor three temperature zones

Tag A = Engine (sensor 28000013406C1001)
Tag B = Cabin (sensor 28000013406C1002)
Tag C = Cargo (sensor 28000013406C1003)

Configure thresholds:

>SXATO01A+0950<    ← Slot 0: Engine > 95.0°C (overheat)
>SXATO11B-0050<    ← Slot 1: Cabin < 5.0°C (underheat)
>SXATO21C+0600<    ← Slot 2: Cargo > 60.0°C (overtemp)

Create event to report any threshold:

>SED00NA0;F21+<   ← Report when F21 rises

Query configured thresholds:

>QXATO0<
>RXATO0A+0950<

>QXATO1<
>RXATO1B-0050<

>QXATO2<
>RXATO2C+0600<

Related Commands

• XATI — Temperature Sensors Info (query sensor list and current values)
• XATL — Temperature Sensor List (manage sensor tags A–J)

Related Features

• Signal F21 — OneWire temperature exceeded critical threshold
• Extended tag TO — Include temperature sensor values in reports

Notes

• Thresholds persist across device resets
• Up to 10 independent threshold conditions can be active simultaneously
• Each threshold monitors one specific sensor (tag)
• Threshold checks occur automatically; signal F21 is triggered continuously while condition is met
• Use event rising-edge logic (F21+) to report threshold violation once per crossing