Dahua DHI-ARM9A4-P-W2 Wireless Multi-I/O Alarm Transmitter with 16 Inputs, 4 Relay Outputs & PoE

Product SKU: DHI-ARM9A4-P-W2

Product Overview

Key Capabilities

Best For

• Existing Wired Alarm Upgrades: Connects conventional wired detectors and outputs to a compatible Dahua wireless alarm architecture.
• Commercial Buildings: Supports multiple supervised zones, relay-controlled devices and backup power from one indoor enclosure.
• Warehouses and Workshops: Integrates wired perimeter sensors, door contacts, sirens and compatible alarm circuits.
• Hybrid Alarm Installations: Uses wireless radio where network cabling is unavailable or Ethernet where a wired hub connection is preferred.
• Expanded Alarm Outputs: Adds four relay channels and auxiliary device power to a supported alarm system.

Why Choose the DHI-ARM9A4-P-W2

The DHI-ARM9A4-P-W2 provides a practical bridge between established wired alarm devices and a compatible Dahua wireless alarm hub. Its 16 supervised inputs support multiple end-of-line configurations, while four 30V DC, 3A relay outputs and two auxiliary power outputs accommodate more complex detector, siren and control requirements than a basic wireless input module. Ethernet and encrypted 433MHz communication give installers flexibility when planning the hub connection, and PoE+ can simplify deployment where suitable network infrastructure already exists. Available through Security Wholesalers, this transmitter is best specified from a complete zone and load schedule. It is not a standalone alarm controller, and the hub, detectors, sirens, backup battery and connected relay loads must all be selected and configured separately.

Buyer Decision Tips

Key Features & Technical Specifications

Product Type	Wireless and Ethernet multi-I/O alarm transmitter for compatible Dahua alarm systems.
Model	DHI-ARM9A4-P-W2.
Alarm Inputs	16 local supervised alarm-input channels.
Zone Wiring Support	0EOL, EOL, 2EOL and 3EOL across inputs 1–16.
Pulse Detection	Supported on alarm inputs 1–6.
Maximum Wired Zone Distance	Up to 500m under Dahua’s specified cable and interference conditions.
Relay Outputs	Four local channels rated up to 30V DC and 3A each.
Auxiliary Power Outputs	Two built-in 14.5V outputs for compatible wired detectors and sirens.
Auxiliary Output Capacity	1A total with PoE power or 2A total with non-PoE power.
Network Connection	One 10/100Mbps RJ-45 Ethernet port.
PoE	IEEE 802.3at PoE+.
Wireless Frequency	433MHz.
Wireless Communication	Two-way radio with frequency hopping and AES128 encryption.
Wireless Range	Up to 1,200m in open space.
Transmitter Power Limit	10mW EIRP.
AC Power	100–240V AC, 50/60Hz.
Backup Battery	Supports one optional 12V 7Ah battery; battery is not included.
Listed Standby Time	Up to 30 hours of static standby operation.
System Monitoring	Tamper detection and low-battery detection.
Local Controls	One switch button and one reset button.
Status Indicator	One built-in status indicator.
Firmware Updates	Cloud update supported.
Installation	Indoor wall mounting.
Protection Rating	IP30.
Casing and Colour	White PC and ABS enclosure.
Operating Conditions	-10°C to +50°C at 10%–90% relative humidity.
Storage Conditions	-10°C to +55°C at 10%–90% relative humidity.
Anti-Corrosion Level	Basic protection.
Certification	CE.
Dimensions	304 × 235 × 90.8mm.
Weight	Net weight 1.22kg; gross weight 1.78kg.

Ideal Use Cases

Choosing the Right Model

• Choose this model if: The system needs 16 wired inputs, four relay outputs and connection to a compatible Dahua wireless alarm hub.
• Choose a smaller input module if: Only a few wired detectors need to be added and no high-capacity relay outputs are required.
• Use PoE+ if: Suitable structured cabling is available and the connected auxiliary-device load remains within the 1A limit.
• Use AC power if: The system requires up to 2A of combined auxiliary output for compatible wired devices.
• Confirm the alarm hub first if: Wireless protocol, firmware, zone supervision and relay integration have not been verified.

FAQs

1. What is the Dahua DHI-ARM9A4-P-W2 used for?
   The DHI-ARM9A4-P-W2 is a multi-I/O transmitter that connects wired alarm detectors, sirens and other compatible devices to a Dahua wireless alarm system. It provides 16 supervised alarm inputs, four relay outputs and two auxiliary power outputs. Communication with the alarm hub can use the 433MHz wireless link or Ethernet, allowing existing wired alarm zones to be incorporated into a supported hybrid installation.
2. Can the ARM9A4-P-W2 connect to the alarm hub through both wireless and Ethernet?
   Yes. The transmitter supports two-way 433MHz wireless communication and a 10/100Mbps Ethernet connection. Dahua lists a wireless range of up to 1,200 metres in open space, together with AES128 encryption and frequency hopping. Actual wireless performance depends on walls, metal structures, interference and installation position, while Ethernet requires a suitable network route to the compatible alarm hub.
3. What alarm-zone wiring does the transmitter support?
   All 16 alarm inputs support 0EOL, EOL, 2EOL and 3EOL zone configurations, allowing compatible wired detector circuits to be supervised according to the chosen design. Inputs 1 to 6 also support pulse detection. Dahua lists a maximum wired connection distance of 500 metres using the specified cable conditions and where strong electrical interference is not present.
4. What can the four relay outputs control?
   The unit provides four local relay-output channels rated up to 30V DC and 3A each. They can be used with compatible alarm devices or control circuits when the connected load remains within the relay rating and the complete wiring design is appropriate. The relays do not supply unlimited device power, so sirens, locks or other equipment may require separate power and suitable protection.
5. How can the DHI-ARM9A4-P-W2 be powered?
   The transmitter supports 100–240V AC at 50/60Hz or PoE+ under IEEE 802.3at. It also accepts an optional 12V 7Ah storage battery for standby operation, with a listed static standby time of up to 30 hours. The battery is not included. Available standby time varies with battery condition, connected loads, auxiliary-output use and the selected primary power method.
6. How much auxiliary power is available for wired devices?
   Two built-in auxiliary outputs provide 14.5V power for compatible wired detectors and sirens. Their combined available current is listed as 1A when the transmitter is powered through PoE and 2A when it uses non-PoE power. The total load from all connected devices must remain within the applicable limit, with allowance for startup current and battery-backed operating requirements.
7. Does the transmitter provide tamper and low-battery monitoring?
   Yes. The DHI-ARM9A4-P-W2 supports tamper detection and low-battery detection, helping the alarm system identify enclosure interference or a weakening backup battery. It also includes a status indicator, a switch button and a reset button, and supports cloud-based firmware updates. These functions must be correctly configured and tested with the compatible alarm hub during commissioning.
8. Is the ARM9A4-P-W2 suitable for outdoor installation?
   No. The transmitter is specified for indoor wall mounting and has an IP30 protection rating with basic anti-corrosion protection. It should be installed in a dry, controlled location within its -10°C to +50°C operating range. When planning through Security Wholesalers, provide the alarm-hub model, zone types, relay loads and power method so system compatibility and auxiliary-power capacity can be checked before installation.

Additional Information

Dahua DHI-ARM9A4-P-W2 Datasheet