Understanding Logic Units, Logic Devices, and Legacy devices
| Feature | Logic Device | Logic Unit | Logic Unit X |
|---|---|---|---|
| Status | Current | Current | Legacy |
| Setup Method | Visual pairing wizard | Quick add | Quick add |
| Input Configuration | Zone/room selection | Manual JSON | Manual JSON |
| Input Count | Dynamic (2-10, auto-expands) | Dynamic (2-10, auto-expands) | Fixed (2, 3, 4...10) |
| Formulas Per Device | Single formula | Multiple formulas | Multiple formulas |
| State Changed Trigger | ✓ Yes | ✗ No | ✗ No |
| Best For | Simple setups, beginners | Advanced users, multi-formula | Not recommended |
⚠️ Legacy Devices
Logic Unit X (2, 3, 4...10 inputs) devices are still functional but deprecated. Use Logic Device or Logic Unit for new setups.
The easiest way to create boolean logic devices with a visual pairing wizard.
1. Devices → Add Device → Boolean Toolbox → Logic Device
2. Pairing wizard:
3. Device Settings → Configure formula:
[
{
"id": "motion_light",
"name": "Motion & Dark",
"expression": "A AND B",
"enabled": true
}
]
Powerful device for advanced users who need multiple formulas or prefer JSON configuration.
[
{
"id": "day_mode",
"name": "Daytime Security",
"expression": "A AND B",
"enabled": true,
"timeout": 60
},
{
"id": "night_mode",
"name": "Nighttime Security",
"expression": "A OR B OR C",
"enabled": true,
"timeout": 30,
"firstImpression": true
},
{
"id": "away_mode",
"name": "Away Mode",
"expression": "(A OR B) AND NOT C",
"enabled": false
}
]
Each formula maintains its own input states and can be controlled independently.
Both Logic Device and Logic Unit share these standard capabilities:
The formula result (true/false)
Enable/disable the device
Both Logic Device and Logic Unit automatically expand inputs based on your formula requirements:
"expression": "A AND B AND C AND D"💡 Tips
⚠️ Important: No Flow Isolation
Within a formula, there is no isolation between flows. This is by design to allow formulas to work across multiple flows.
Scenario: Multiple flows using the same formula
Flow 1: Set input A = true for formula "security"
Flow 2: Set input B = true for formula "security"
Flow 3: Triggered when formula "security" = true
Result: Flow 3 triggers when (A AND B) from different flows!
If you need to use the same logic in multiple places within one flow with isolated states:
Solution: Create Multiple Device Copies
💡 Pro Tip
For Logic Unit with multiple formulas: Each formula IS isolated from each other (formula "A" doesn't affect formula "B"), but each individual formula can be accessed from any flow.
⚠️ Legacy Device Warning
Logic Unit X (2, 3, 4...10 inputs) devices have fixed input counts and should be migrated to the new dynamic devices.
Go to old device settings → Copy the entire formula JSON
Verify all formulas evaluate correctly with test inputs
Replace old device references with new device in all flows
Once verified, delete the legacy Logic Unit X device
✅ Benefits After Migration
Name devices and formulas clearly: "Motion Light - Living Room" instead of "Logic 1"
Begin with Logic Device for single formulas, upgrade to Logic Unit when you need multiple formulas
Use the Boolean Logic Emulator to verify expressions before deploying
Create separate device copies when you need the same logic with isolated states
Don't worry about input count during setup - devices expand automatically based on your formulas