1. Introduction
The LTECH DMX/RDM LED Decoder series (LT-903, LT-904, LT-905 and their DIP/OLED variants) are advanced constant voltage DMX512 decoders designed for controlling RGB, RGBW, and RGBWY LED lighting systems. These decoders feature DMX512 and RDM (Remote Device Management) protocols, offering flexible control and configuration options. They are built with photoelectric isolation for improved signal transmission efficiency and anti-interference ability, ensuring reliable performance in various lighting applications.
Key features include:
- 3, 4, or 5 channel output options.
- High current capacity per channel (up to 8A for 3CH, 6A for 4CH, 5A for 5CH).
- 8-bit (256 levels) or 16-bit (65536 levels) grey level options for smooth dimming.
- Multiple DMX interfaces: 3-pin XLR and RJ45.
- Built-in protection against short circuit, over current, and overheating with automatic recovery.
- Digital display and DIP switches for easy parameter setting and self-testing.
- RDM remote management for advanced configuration and firmware upgrades.
2. Safety Precautions
Please read and follow these safety guidelines carefully to ensure safe operation and prolong the lifespan of your product:
- Professional Installation: Products must be installed by qualified professionals.
- Environmental Conditions: LTECH products are generally non-waterproof (special models excepted). Avoid direct sun and rain. If installed outdoors, ensure it is mounted in a waterproof enclosure.
- Ventilation: Ensure good heat dissipation. Reserve enough ventilation distance (no less than 20mm) between decoders. Do not block the vent, as it may affect the decoder's lifetime due to poor heat dissipation.
- Power Supply: Check that the working voltage used complies with the parameter requirements of the product.
- Wiring: The diameter of the wire used must be able to load the light fixtures you connect and ensure firm wiring. Before powering on, make sure all wiring is correct to prevent damage to light fixtures.
- Faults: If a fault occurs, do not attempt to fix the product yourself. Contact your official distributors or supplier for assistance.
3. Technical Specifications
| Feature | Description |
|---|---|
| Input Signal | DMX512/RDM |
| DMX Interfaces | 3-pin XLR, RJ45 |
| Input Voltage | 12-24Vdc |
| Photoelectric Isolation | Yes |
| Protection | Short circuit / Overheat / Over current protection (automatic recovery) |
| Working Temperature | -30°C ~ 65°C |
| Dimensions (LxWxH) | 122mm × 110mm × 37mm |
| Package Size (LxWxH) | 127mm × 123mm × 41mm |
| Weight (G.W.) | 550g |
| Grey Levels | 8bit (256 levels) / 16bit (65536 levels) |
| Certifications | CCC, CE, CQC, EMC, FCC, LVD, ROHS, UL, cURus, TUV |
| Model | Channels | Current Load | Output Power |
|---|---|---|---|
| LT-903 / LT-903-DIP | 3CH | 8A / CH, Max. 24A | (0-96W...192W) × 3CH, Max. 576W |
| LT-904 / LT-904-DIP | 4CH | 6A / CH, Max. 24A | (0-72W...144W) × 4CH, Max. 576W |
| LT-905 / LT-905-OLED | 5CH | 5A / CH, Max. 25A | (0-60W...120W) × 5CH, Max. 600W |
4. Product Components
The LTECH DMX/RDM LED Decoders feature a user-friendly design with a digital display, DIP switches, and clearly labeled input/output terminals.
4.1 DMX Interfaces
The decoders are equipped with various DMX interfaces to ensure compatibility and flexibility in different setups:
- 3-pin XLR: Standard DMX input and output.
- RJ45: Alternative DMX input and output, often used for network-style cabling.
- Green Terminals: Screw terminals for power input and LED output connections.
5. Installation
5.1 Connecting LED Lights
Connect your LED lights to the decoder's output terminals. Ensure correct polarity (V+ and channel outputs) and that the total current load does not exceed the maximum rating for the specific decoder model.
5.2 DMX Console Connection
Connect the DMX console to the decoder using either 3-pin XLR or RJ45 cables. Multiple decoders can be connected in parallel. Ensure proper signal chain and termination.
- An amplifier may be needed if more than 32 decoders are connected or if using an overlong signal line. Signal amplification should not be more than 5 times continuously.
- To prevent signal reflection effects from longer signal lines or poor line quality, connect a 0.25W 90-120Ω terminal resistor at the end of each DMX line.
6. Operation
6.1 Digital Display and DIP Switch
The digital display shows current settings, and the DIP switches allow for mode selection and DMX address configuration. The display will enter a locked mode without operating after 15 seconds. Use the 'M' key to unlock and switch entries, and the arrow keys to adjust values.
6.2 DIP Switch Modes
- RDM Mode: DIP switches 1-10 are all OFF.
- DMX Mode: FUN=OFF (the 10th DIP switch = OFF). Use DIP switches 1-9 to set DMX addresses.
- Self-testing Mode: FUN=ON (the 10th DIP switch = ON).
6.3 Setting DMX Address via DIP Switch (DMX Mode)
In DMX mode (10th DIP switch OFF), the DMX address value is the total value of DIP switches 1-9 that are in the "ON" position. If a switch is OFF, its value is 0.
Examples:
- To set initial address to 32: Turn ON DIP switch 6 (value 32).
- To set initial address to 37: Turn ON DIP switches 1 (1), 3 (4), 6 (32). Total = 1+4+32 = 37.
- To set initial address to 178: Turn ON DIP switches 2 (2), 5 (16), 7 (64), 8 (128). Total = 2+16+64+128 = 178.
When DIP switches 1-9 are all OFF, the default initial DMX address is 1.
6.4 Self-testing Mode
When the 10th DIP switch is ON (FUN=ON), the decoder enters self-testing mode. DIP switches 1-9 can be used to select various static colors, jumping effects, or gradient effects. DIP switches 1-7 can also be used to realize 7 speed levels (7=ON for the fastest level).
If several DIP switches are ON, the effect will be determined by the highest switch value.
6.5 DMX Dimming Instruction
Each DMX decoder occupies a specific number of DMX addresses. For example, the LT-903-DIP decoder occupies 3 DMX addresses. The default initial address is 1. The DMX console channels correspond to the decoder's PWM outputs as follows:
| DMX Console | DMX Decoder |
|---|---|
| CH1 0-255 | PWM 0-100% (LED R) |
| CH2 0-255 | PWM 0-100% (LED G) |
| CH3 0-255 | PWM 0-100% (LED B) |
| CH4 0-255 (for 4/5CH models) | PWM 0-100% (LED W) |
| CH5 0-255 (for 5CH models) | PWM 0-100% (LED Y) |
6.6 Dimming Curves
The decoders support various dimming curves to achieve different lighting effects, including Standard, Linear, LOG, and customized curves ranging from 0.1 to 9.9.
7. App Control (RDM Editor)
For advanced parameter setting and remote management, the LTECH DMX/RDM decoders can be controlled via the RDM Editor App using a WiFi-RDM01 device. This allows for remote programming operations such as browsing and setting parameters, DMX address settings, equipment recognition, and firmware upgrades, eliminating the need for physical access during installation and setup.
To use this feature, download the RDM Editor App and connect it to the WiFi-RDM01, which then communicates with the decoders.
8. Maintenance & Troubleshooting
8.1 General Maintenance
- Keep the device clean and free from dust.
- Ensure adequate ventilation to prevent overheating.
- Regularly check all wiring connections for tightness and integrity.
8.2 Troubleshooting
The decoders are equipped with automatic protection features:
- Short Circuit Protection: The device will automatically recover once the short circuit is resolved.
- Over Current Protection: The device will automatically recover once the over current condition is resolved.
- Overheat Protection: The device will automatically recover once the temperature returns to a safe operating range.
If the device is not functioning correctly and the issue is not resolved by these automatic protections, or if you suspect a fault, please do not attempt repairs yourself. Contact your official distributor or supplier for technical support.
9. User Tips
- For optimal DMX signal integrity, always use a DMX terminator at the end of your DMX chain.
- When planning your installation, consider the total power consumption of your LED fixtures to ensure it does not exceed the decoder's maximum output power.
- Utilize the RDM Editor App for complex setups or when decoders are installed in hard-to-reach locations, as it simplifies parameter adjustments and diagnostics.
- Periodically check for firmware updates via the RDM Editor App to ensure your decoders have the latest features and bug fixes.
10. Warranty & Support
10.1 Warranty Agreement
LTECH products come with a 5-year warranty from the date of delivery. Free repair or replacement services are provided for quality problems that occur within the warranty period.
Warranty Exclusions:
- Beyond warranty periods.
- Any artificial damage caused by high voltage, overload, or improper operations.
- Products with severe physical damage.
- Damage caused by natural disasters and force majeure.
- Warranty labels and barcodes have been damaged.
- No contract signed by LTECH.
Repair or replacement provided is the only remedy for customers. LTECH is not liable for any incidental or consequential damage unless it is within the law.
LTECH has the right to amend or adjust the terms of this warranty, and release in written form shall prevail.
10.2 Technical Support
For any questions, technical assistance, or warranty claims, please feel free to contact your official LTECH distributors or the supplier from whom you purchased the product.