Allen Bradley 1790-0W8X CompactBlock LDX I/O Expansion Block
Allen Bradley 1790-0W8X CompactBlock LDX I/O Expansion Block
0.0
Points
Brand:Allen Bradley PLC Item No.:1790-0W8X Product Origin:USA Product Dimensions:104 x 42 x 52 mm Product Weight:0.1 kg Payment:T/T, Western Union, Credit Card Goods_stock:15 Shipping Port:Xiamen, China Lead Time:1-3 Days Condition:Brand New And Original Warranty:1 Year Certificate:COO
The Allen Bradley 1790-0W8X CompactBlock LDX I/O Expansion Block is an eight-point relay output module developed for distributed industrial automation applications. As part of the Bulletin 1790 CompactBlock LDX family, it allows compatible DeviceNet I/O systems to add relay switching functions without requiring a complete change to the existing control architecture.
The module features eight Form A normally open relay contacts, with a resistive-load rating of 2.0 A at 5–24 V DC or 30 V AC. Each output has a dedicated status indicator, making it easier for technicians to monitor switching conditions during operation and maintenance.
Its photocoupler isolation separates the I/O circuits from the logic circuits, while the 37-pin D-shell connector provides a structured field wiring interface. The module requires a nominal 24 V DC field supply and is designed for installation as part of a compatible CompactBlock LDX expansion assembly.
The 1790-0W8X is suitable for legacy DeviceNet installations, machine upgrades, and industrial equipment maintenance where relay-based output control is required. Before installation, engineers should verify the electrical characteristics of the connected loads, particularly when switching inductive equipment.
When selecting the 1790-0W8X for replacement or maintenance, confirm the complete catalog number, relay contact ratings, connector configuration, and compatibility with the existing DeviceNet installation.
Applications
The Allen Bradley 1790-0W8X CompactBlock LDX I/O Expansion Block is an 8-channel relay output expansion module designed for DeviceNet-based industrial automation systems. It provides relay switching capability for compatible AC and DC field loads, allowing users to expand the output capacity of an existing CompactBlock LDX installation.
Typical applications include:
Industrial Machine Control: Switches compatible auxiliary devices and control circuits.
Conveyor Systems: Provides relay outputs for motors, signaling devices, and interface circuits.
Packaging Equipment: Supports discrete switching functions in automated production lines.
Process Automation: Controls compatible field devices through relay contacts.
Control Panel Integration: Adds relay output points to distributed I/O assemblies.
Equipment Upgrades: Expands the control capabilities of existing DeviceNet automation systems.
Key Features and Advantages
1. Eight Relay Output Channels
The module provides eight independent relay output points, offering flexible switching capability for industrial control applications.
2. Form A Normally Open Contacts
Each output uses a Form A, single-pole single-throw normally open relay contact, making it suitable for switching compatible external loads.
3. AC and DC Load Switching
The relay contacts support specified resistive AC and DC loads, allowing the module to serve different industrial switching requirements.
4. Individual Channel Status Indicators
Eight green LED indicators provide visual output-status information, helping maintenance personnel monitor module operation.
5. Photocoupler Isolation
Photocoupler isolation between the I/O and logic circuits helps separate field-side electrical circuits from internal control electronics.
6. Compact D-Shell Connection
The 37-pin D-shell connector provides an organized wiring interface and supports integration into compatible CompactBlock LDX installations.
7. Flexible Distributed I/O Expansion
The module adds relay output capacity to a compatible CompactBlock LDX base block, supporting modular system expansion.
Technical FAQs
Q1: How many relay outputs does the 1790-0W8X provide?
It provides eight relay output channels, each with an individual normally open contact.
Q2: What type of relay contacts are used?
The module uses Form A, single-pole single-throw normally open contacts.
Q3: What is the maximum switching current?
The specified resistive-load rating is 2.0 A per output for 5–24 V DC and 30 V AC. Always observe the applicable voltage and load limitations.
Q4: Can the module switch both AC and DC loads?
Yes. It supports specified AC and DC resistive loads. The actual load voltage and current must remain within the relay contact ratings.
Q5: What is the field power requirement?
The module requires a nominal 24 V DC field supply, with a specified operating range of 19.2–28.8 V DC.
Q6: Does the module have individual output indicators?
Yes. Eight green status LEDs provide visual indication for the relay output channels.
Q7: What is the maximum output switching delay?
The maximum delay is 10 ms from OFF to ON and 10 ms from ON to OFF.
Q8: What is the expected relay contact life?
The specified expected contact life is approximately 300,000 cycles for resistive loads and 100,000 cycles for inductive loads. Actual service life depends on switching frequency and load characteristics.
Q9: What isolation does the module provide?
It uses photocoupler isolation between the I/O and logic circuits, with a specified isolation voltage of 1250 V AC RMS.
Q10: What should be checked before replacing this expansion block?
Verify the relay contact configuration, field supply voltage, load type, current requirements, D-shell connector wiring, and compatibility with the installed CompactBlock LDX base block.
