JMD Command — Jamming Detection

Detects the presence of jammers or cellular signal inhibitors.

What is it for?

🚨 Main use cases:

🔒 Alert about signal inhibition attempts
📡 Detect jamming attacks on vehicles
⚡ Activate emergency outputs upon interference
📊 Log inhibition events for analysis
🛡️ Anti-theft security for fleets

Jamming affects data transmission via GPRS, SMS and audio. This signal allows detecting when the device is being jammed.

Description

The JMD signal activates when the equipment detects interference that disrupts communications. It remains active for the duration of the inhibition and can be used as a trigger or conditional in the event engine.

Examples

Basic rule - Activate output upon jamming


>SRL56E;TRG=JMD+;ACC={SSSXP0011}<    // When jamming detected, activate output XP00

Complete jamming monitoring system


>STD15E00002<    // Timer every 2 seconds for monitoring
 
>SRL90E;TRG=JMD+;ACC={GCQ00L;TXT=JAMMING DETECTED!!!}<    // When jamming starts
>SRL91E;TRG=JMD-;ACC={GCQ00L;TXT=JAMMING OFF}<             // When jamming ends
 
// Continuous status monitoring
>SRL92E;TRG=TD15+;CND=JMD;ACC={GCQ00L;TXT=UNDER JAMMING}<              // If under jamming
>SRL93E;TRG=TD15+;CND=JMD!;ACC={GCQ00L;TXT=NORMAL OPERATION}<          // If NOT under jamming

Usage in Rules

Usage	Syntax	Description
Start trigger	`TRG=JMD+`	When jamming detected
End trigger	`TRG=JMD-`	When jamming ends
Active conditional	`CND=JMD`	If being jammed
Negated conditional	`CND=JMD!`	If NOT being jammed

Associated Signals

Property	Value
Signal	`JMD`
Index	No index
Conditional usage	✅ YES
Edges	`+` start, `-` end, both

Compatibility

💾Firmware v1.10.00

SPLegacy

ULLegacy

MTLegacy

💾Firmware v1.00.00

SP-IOT

SM-IOT