Pulse polarity A
A Casambi ON transition drives Relay A positive relative to Relay B for the configured duration.
A +− B
The latching mechanism moves to the commissioned ON
state.
CASAMBI ENABLED · PANEL RELAY CONTROL
casDouglas
Bring legacy panel relays into a modern Casambi network.
Douglas-style electrical-panel relays switch branch circuits with a short DC pulse—one polarity to set the relay and the opposite polarity to reset it. casDouglas generates those pulses directly and adds programmable low-voltage input and output points.
MADE IN USADesigned, built and supported in Mesa, Arizona
CASAMBI → casDouglas → PANEL RELAY → CIRCUIT
RELAY ARELAY B
A short reversing pulse changes the relay state. Then coil power returns to zero.
12–24 VDCClass 2 input supply
250–3000 msprogrammable relay pulse
1 in + 1 outprogrammable low-voltage digital I/O
THE RELAY REMEMBERS · THE COIL DOES NOT STAY POWERED
Set it. Reset it.
Let it hold.
The H-bridge is the practical way to put either polarity across the same two relay-coil wires. casDouglas applies the selected pulse, verifies the command path, then disables the bridge.
Reverse the pulse
An OFF transition drives the same two wires with opposite polarity. Output Polarity can swap which direction represents ON.
A −+ B
The latching mechanism moves to the commissioned OFF
state.
Bridge disabled
The output returns to high impedance. The mechanical relay remains in its last state without continuous coil power.
A 00 B
No steady coil drive between state changes.
INTERACTIVE PANEL-RELAY DEMO
Watch one command become
one deliberate pulse.
Choose the pulse duration, command the relay, and see Relay A/Relay B reverse. This browser demonstration illustrates behavior; it does not configure hardware.
Commissioning controls
Start with the shortest pulse that reliably transfers the approved relay at worst-case voltage and temperature.
ELECTRICAL PANEL
Controlled branch circuit
LATCHING
RELAY COIL
RELAY COIL
casDouglas OUTPUTBridge asleep
RELAY A0 V
RELAY B0 V
PULSEREADY
Ready. The H-bridge is disabled and the relay retains its last mechanical state.
A FAMILIAR PANEL · A NEW CONTROL PATH
Designed for the circuits
contractors already know.
Use the existing two-lead, polarity-controlled latching relay as the boundary between Class 2 control and the branch circuit it already switches.
Panel relay remains
The approved Douglas-style relay continues to perform the branch-circuit switching job inside the electrical panel.
Casambi at the coil
casDouglas connects to the relay’s two-wire coil circuit and translates network state changes into timed polarity pulses.
Contractor-readable control
Name the device for the panel, room, or controlled circuit so commissioning and service records match the electrical schedule.
Test set and reset
Measure opposite polarity during ON and OFF, verify zero volts afterward, and confirm the intended circuit state.
THE RELAY IS ONLY PART OF THE JOB
One local input.
One local output.
The input brings a voltage-free field contact into Casambi. The output is a ground-referenced solid-state sink for a compatible low-energy contact-sense input.
FIELD INPUTButton, maintained switch or relay contact
→
CONTACT IN / OUT + GROUNDcasDouglas
→
FIELD RESULTCasambi command + electronic contact
DRY CONTACT INVoltage-free input
Ready · external voltage-free contact open
DRY CONTACT OUTLow-side electronic output
Electronic contact released
Low-energy interface only: this is not an isolated relay contact. Use only with the released project voltage/current rating and a compatible Class 2 contact-sense input.
Closure and opening report ON/OFF, with optional action inversion.
Each debounced closing edge changes the stored state once.
Choose fixed or alternating dim direction and endpoint behavior.
Keep compatible NED stations aligned on level and next dim direction.
MULTISWITCH GANG 1–10
Keep separated switches
in the same logical state.
Give the casDouglas dry input and compatible NED inputs the same Gang number. Level and dim-direction memory move across the Casambi mesh, eliminating the first press that otherwise only catches up stale local state.
PANEL LOCATIONcasDouglas inputOperated contact updates Gang
⇄
CASAMBI MESHGANG 1–10Shared level + direction
⇄
REMOTE STATIONCompatible NED inputNext action starts synchronized
FIVE VENDOR PARAMETERS
Match the relay.
Shape the wall control.
Commission pulse direction and duration first, then set the local input behavior and dry-output polarity.
IDParameterWhat it controls
0Output Polarity
Swaps which pulse direction represents relay ON and OFF
1Hold Duration
Coil pulse length: 250–3000 ms supported by product documentation
2Dry In Action
Normal, inverted or MultiSwitch Gang 1–10
3Dry In Mode
Static, pulsed, hold-dim or double-tap behavior
4Dry Out Polarity
Normal or inverted electronic-contact state
After editing parameters, leave the node powered until Casambi completes the parameter write. Then verify values through a controlled power cycle.
CLASS 2 CONTROL AROUND A PANEL RELAY
Two coil wires.
No center tap. No ground.
Power casDouglas from a polarity-correct 12–24 VDC Class 2 supply sized for the controller plus the relay’s measured pull-in current.
12–24 VDC
Class 2 supply
→
Class 2 supply
casDouglasRELAY A / RELAY BCONTACT IN / CONTACT OUT / GROUND
TWO-LEAD LATCHING RELAYApproved Douglas-style coil
Installation essentials
- Supply
- 12–24 VDC Class 2
- Relay output
- Two-terminal, reversing timed pulse
- Application current
- Up to 2 A, load dependent
- Pulse
- 250–3000 ms
- Environment
- Indoor, open-type device
Do not connect either relay-coil lead to ground, use a center-tapped coil without an approved interface, or add a single flyback diode across a polarity-reversing coil.
PLAN · INSTALL · COMMISSION
Take the details
to the panel.
Use the installation guide for ratings and terminal connections, then the commissioning guide for pulse proof, parameters, I/O and acceptance testing.
Installation manual
User Guide v1.04
Ratings, connection diagram, relay output and dry-contact wiring.Commissioning guide
Engineering review copy
Profiles, pulse verification, five parameters, MultiSwitch and testing.Have a panel relay application?
Bring us the relay model, coil voltage/current, panel schedule and control sequence.