Viking Software for the TDR-1 (Sold w/ TDR-1) - TDF-DOI

Viking Electronics TDF-DOI Time Delay Relay

The Viking Electronics TDF-DOI is a configurable time delay relay designed to automate sequenced switching across a wide range of access control, door hardware, and facility automation applications. Sold with the TDR-1 relay module, the TDF-DOI provides the software configuration layer that makes the TDR-1 field-programmable without external tools — giving integrators direct control over delay behavior at the point of installation. If you're wiring door strikes, gate controllers, or interlock sequences where a fixed, reliable time delay between trigger and release is non-negotiable, the TDF-DOI paired with the TDR-1 is a purpose-built solution for exactly that.

Key Features

• 8 Selectable Delay Steps (1–30 Seconds): Rather than a continuous analog pot that drifts over time, the TDF-DOI provides 8 discrete, repeatable delay settings across a 1-to-30-second range. For a door strike that needs to hold open exactly 5 seconds after a valid credential, you set it once and it stays set — no field recalibration required.
• Single DPDT Relay Output: The double-pole double-throw (DPDT) configuration gives you both normally-open and normally-closed contacts on one relay, so you can drive a load and simultaneously signal a panel or indicator without adding an external relay. At 1A @ 30VDC, it's rated for typical door hardware — electric strikes, maglocks via an intermediate relay, and signal devices.
• AC Load Capability (0.5A @ 125VAC): The relay contacts handle 125VAC at 0.5A, which covers most low-current AC loads like chimes, annunciators, or HVAC interlocks. This eliminates the need for an additional relay board in mixed AC/DC control panels.
• 12V DC Operating Voltage with Included AC Adapter: The TDR-1 unit runs on 12V DC, and the 120V AC to 12V DC adapter ships in the box — you're powered from a standard outlet without sourcing a separate wall wart or integrating a panel power supply for basic deployments. For panel-fed installs, wire directly to an existing 12V rail.
• Compact 2.9" × 2.1" × 1.0" Footprint: At under 3 inches in its longest dimension, the TDR-1/TDF-DOI fits inside standard single-gang enclosures, behind door frame trim, or inside access control panel housings with no modification. Weight under 1 lb means no special mounting reinforcement.
• Operating Range 32°F–90°F (0°C–32°C) with 5–95% RH Non-Condensing: The specified operating temperature covers conditioned indoor environments — lobbies, server closets, reception areas, and interior door frames. This is an indoor-rated device; do not deploy in unheated vestibules, exterior panels, or high-humidity mechanical rooms where condensation is possible.
• High-Voltage DC Switching (0.3A @ 110VDC): The relay is rated for 110VDC switching at 0.3A — useful in industrial interlock and elevator control applications where DC bus voltages are elevated. Most access control integrators won't use this, but it opens the door to light industrial sequencing without an additional isolation relay.
• 2-Year Limited Warranty: Viking backs the TDR-1/TDF-DOI with a 2-year limited manufacturer warranty — longer than the 1-year coverage common among commodity relay modules in this price range.

Integration and Compatibility

The TDF-DOI is the software/configuration component sold exclusively with the TDR-1 time delay relay — they function as a single deployable unit. The TDR-1 integrates into any system that outputs a trigger signal: access control panels (Honeywell, Bosch, Lenel, and others via dry contact or voltage trigger), intercom systems with relay trigger outputs, and PLC or BMS systems with relay or open-collector outputs. Because the output is a standard DPDT relay, downstream compatibility is universal — the TDR-1 is protocol-agnostic and simply switches contacts.

For integrators building out door control systems, the TDF-DOI/TDR-1 pairs naturally with door access control hardware including electric strikes and maglocks. It also complements Viking's own intercom and door entry product line — see the full Viking Electronics catalog for compatible entry systems. When planning power distribution for multi-door deployments, consult a PoE switch or power distribution guide to determine whether centralized 12V power or local adapters best suit your panel layout. For broader relay and control sequencing projects, the access control category covers complementary hardware including power supplies and lock hardware.

Frequently Asked Questions

Q: What delay times are available on the TDF-DOI / TDR-1?

A: The TDF-DOI provides 8 selectable delay settings spanning 1 to 30 seconds. The specific increments within that range are set via the configuration software — you are not limited to a fixed set of predetermined values like 5/10/15/30.

Q: What is the relay output type and load rating?

A: The TDR-1 features a single DPDT (double-pole double-throw) relay output rated at 1A @ 30VDC, 0.3A @ 110VDC, and 0.5A @ 125VAC. This covers typical door strike, annunciator, and low-current AC load applications.

Q: Is the TDF-DOI suitable for outdoor or unheated enclosure installation?

A: No. The operating temperature range is 32°F to 90°F (0°C to 32°C) with 5–95% non-condensing humidity. This is an indoor-rated device. Do not install in unheated spaces, exterior enclosures, or environments prone to condensation.

Q: Does the TDR-1 include a power supply?

A: Yes. A 120V AC to 12V DC adapter is included. The unit can also be powered from an existing 12V DC panel supply if preferred.

Q: What is the warranty on the TDF-DOI?

A: Viking Electronics provides a 2-year limited manufacturer warranty on the TDF-DOI / TDR-1.

Q: Can the TDF-DOI be searched as TDF DOI?

A: Yes — the model is sometimes searched without the hyphen as TDF DOI. Both refer to the same Viking Electronics time delay relay configuration software sold with the TDR-1 unit.

Eden Phillips

The TDF-DOI is the configuration piece that makes the TDR-1 worth deploying rather than reaching for a generic off-shelf timer relay. The 8-step discrete delay selection — spanning 1 to 30 seconds — is the practical differentiator here: analog pots drift, DIP-switch increments on cheap modules are fixed and coarse, but the TDF-DOI's software-defined steps give you repeatable, stable timing that holds across temperature swings within the rated 32°F–90°F envelope.

Technical Highlights:

• DPDT Relay Output: Both NO and NC contacts available simultaneously — drive a door strike on one pole and feed a panel input or indicator on the other without adding a relay board. Rated 1A @ 30VDC covers virtually all low-voltage door hardware loads.
• 8 Selectable Delay Steps: 1–30 second range with 8 discrete settings means you're not interpolating on a pot or guessing. Set it in the field, document the step number, and replicate it identically across every door in a multi-entry deployment.
• Included 120V AC Adapter: Ships ready to bench-test or deploy from a standard outlet. For panel installs, drop the adapter and wire directly to the 12V DC bus — no power conversion hardware to source separately.

Deployment Considerations:

• The 90°F (32°C) upper operating limit is tight. In server rooms that run warm or utility closets in summer climates, verify ambient temperature before mounting — exceeding spec shortens relay contact life.
• At 0.5A @ 125VAC, the relay handles chimes and annunciators but is not rated for direct AC maglock switching at typical 500mA–1A lock inrush. Use an intermediate relay or dedicated lock power supply for AC maglocks.

The TDF-DOI/TDR-1 is the right call for intercom-integrated door strike sequencing in commercial lobbies and multi-tenant entry systems — specifically where a Viking intercom is already in the riser and you need a timed strike release that integrates cleanly into the same wiring run without adding a separate panel relay module.