Product Overview
The 3DM476.6 (3DM476.6) is a versatile digital mixed module engineered for the B&R System 2005 series. Designed to handle high-density I/O requirements in a single hardware footprint, this module features 16 digital inputs and high-performance outputs compatible with both 24 VDC and 24 VAC signals. This "mixed" architecture makes the 3DM476.6 an ideal solution for retrofitting legacy systems or managing diverse field devices such as limit switches, sensors, and small solenoid valves. With its robust IP20 protection and comprehensive electrical isolation, this module provides a reliable interface for complex industrial automation tasks in energy management, material handling, and process control.
Hardware Architecture and Signal Logic
The 3DM476.6 is optimized for stability and safety, utilizing advanced group isolation to prevent cross-talk and protect the central processing logic.
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Digital Mixed I/O: Combines input and output functionality, reducing the number of physical slots required in the rack and lowering overall system costs.
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Dual Voltage Compatibility: Supports 24 VDC and 24 VAC field signals, providing unparalleled flexibility when interfacing with mixed-power control cabinets.
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Sophisticated Isolation: Features high-level group isolation (Input to Input and Input to Output). This ensures that electrical faults in one group do not propagate to other sections of the module or the backplane.
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Power Efficiency: Balanced power profile with an external consumption of 2.0 W (24 V) and internal consumption of 2.5 W (5 VDC).
Technical Specifications
| Feature |
Specification Details |
| Model |
3DM476.6 |
| Brand |
B&R (Bernecker + Rainer) |
| Module Type |
Digital Mixed I/O Module |
| Input Channels |
16 |
| Nominal Voltage |
24 VDC / 24 VAC |
| Output Current |
0.4 A |
| Internal Power |
2.5 W at 5 VDC |
| External Power |
2.0 W at 24 V |
| Isolation |
Group Isolation (Input/Input, Input/Output) |
| Protection |
IP20 |
| Shipping Weight |
2.0 kg |
Technical FAQs
Can the 3DM476.6 handle AC and DC signals simultaneously on different channels?
The module is rated for both 24 VDC and 24 VAC, but you must adhere to the group isolation rules. While individual channels are not isolated from one another within a group, the input groups are isolated from output groups, allowing for different potential references across those boundaries.
What is the significance of the 0.4 A output rating?
The 0.4 A rating per output is specifically tailored for driving pilot devices, such as interposing relays or high-impedance solenoid coils. If you need to drive high-power actuators, it is recommended to use the 3DM476.6 to trigger a larger power contactor.
How does the 2.5 W internal power consumption affect my rack sizing?
The 2.5 W drawn from the 5 VDC backplane is a critical factor for your power budget. Ensure that your System 2005 power supply module has sufficient "Internal 5V" headroom to support this module along with other CPU and communication cards in the same rack.
Field Engineering & Installation Guide
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Wiring for Group Isolation: When wiring the 3DM476.6, take advantage of the group isolation to separate noisy AC field signals from sensitive DC inputs. Ensure that common terminals for different groups are kept electrically distinct to maintain the integrity of the isolation barrier.
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Thermal Management: Given the total internal and external power consumption (4.5 W total), ensure the System 2005 rack is mounted in an enclosure with adequate ventilation. If multiple 3DM476.6 modules are used, maintain standard clearance between the rack and the cabinet walls.
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I/O Mapping: Before commissioning in B&R Automation Studio, verify the channel mapping. Since this is a mixed module, improper software configuration can lead to "Output Force" commands being sent to hardware defined as inputs, which may trigger system faults.
Engineering Advantages
The 3DM476.6 represents the rugged engineering standards of B&R's classic automation lines. The 2.0 kg shipping weight is indicative of its high-quality internal components and solid mechanical housing. Its ability to provide 16 inputs plus outputs in a single unit makes it a "space-saver" for dense control panels. Furthermore, the lack of channel-to-channel isolation within a group—balanced by robust group-to-group isolation—provides a cost-effective yet safe solution for standard industrial applications where extreme individual isolation is not required.