GD-04K Versatile GSM Communicator and Controller

Overview

The GD-04K by Jablotron is a compact quad‑band GSM communicator and controller designed for remote switching and event reporting. It is suitable for building monitoring, access control, alarm signalling and smart‑home integrations where reliable GSM communication is required.

Main features

Four inputs (A–D) react to grounding and generate off/on reports via SMS or call. Two power relay outputs (X, Y) can operate as status or pulse outputs; pulse length is configurable from 1 second to 10 hours. When controlled by incoming call, a per‑number limit on control events can be set.

Configuration

Local configuration is available via USB using the free GD‑Link 2.x software; remote configuration is possible through the device’s web settings. A standard 2G SIM card is required — disable the PIN code or preset it to 1234 before use. Prepaid SIM cards are not recommended without monitoring; the device can, however, check prepaid credit if configured.

Power and backup

Operating voltage: 10.5 ÷ 15 V DC. Standby consumption approximately 25 mA (+17 mA per relay); max. consumption during GSM communication up to 200 mA. An optional GD‑04A backup module (sold separately) provides battery backup for continued operation during mains failure (up to ~24 hours depending on battery).

Technical data (key values)

• GSM bands: E‑GSM 850 / 900 / 1800 / 1900 MHz
• RF output power: 2 W (GSM 850/900), 1 W (GSM 1800/1900)
• Outputs X and Y: resistive load max. 2.5 A / 250 V AC; lamp (inductive/capacitive) max. 0.5 A / 250 V AC
• 4 alarm inputs (A–D), triggering by GND
• Up to 100 authorized telephone numbers for control/reporting
• Dimensions (without antenna): 76 x 110 x 33 mm; GSM antenna via SMA connector
• Standards: EN 60950-1; EMC EN 301489-7, EN 55022, EN 61000-6-3; radio ETSI EN 301511

Installer note: verify GSM signal at the installation site and ensure the SIM card PIN is disabled. The unit is intended for indoor use and operates between -10 °C and +40 °C.