Product Details
Module Overview
The 1734-OB8S is a high-reliability POINT Guard I/O module designed for safety-critical applications within the Allen-Bradley (Rockwell Automation) ecosystem. Functioning as a specialized 8-point digital safety output module, it provides the deterministic control required for emergency stops, light curtains, and safety gate interlocks. When integrated into a GuardLogix or SmartGuard controller system via EtherNet/IP or DeviceNet, the 1734-OB8S ensures that safety functions are executed with SIL 3, PLe, and Cat. 4 compliance. Its compact POINT I/O form factor allows for localized safety control, reducing complex wiring runs to the main control cabinet.
Detailed Engineering Specifications
The 1734-OB8S is engineered to provide fail-safe switching of 24V DC field loads while continuously performing internal diagnostics to detect short circuits or ground faults.
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Module Type: POINT Guard I/O Safety Output
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Safety Output Points: 8 Points (Sourcing)
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Nominal Supply Voltage: 24V DC
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Operating Voltage Range: 19.2 to 28.8V DC
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Maximum Output Current: 8.0A total per module (1.0A per point @ 40°C)
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Power Dissipation: 4.5 Watts
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Thermal Dissipation: 15.38 BTU/hour
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Safety Ratings: SIL 3 (IEC 61508), PLe (ISO 13849-1), Category 4
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Backplane Current Draw: 175 mA @ 5V DC
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Point-Level Diagnostics: Short-circuit detection, overload protection, and pulse testing
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Mounting Orientation: Horizontal or Vertical
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Physical Weight: 0.25 lbs (0.11 kg)
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Enclosure Rating: Open-style (IP20)
Advanced Safety and Diagnostic Features
The 1734-OB8S excels in identifying potential hardware failures before they lead to a dangerous state. Each output is capable of performing "Pulse Testing," which momentarily switches the output off and back on (too fast to affect the load) to verify that the switching circuitry is functional and that no external cross-circuit exists. In the event of a detected fault, the module transitions to a safe "Off" state and reports the specific error code back to the safety controller for rapid troubleshooting.
System Requirements and Installation
To utilize the 1734-OB8S, the module must be seated in a 1734-TB or 1734-TBS removable terminal base. It requires a 1734-AENTR (Ethernet) or 1734-PDN (DeviceNet) adapter that supports CIP Safety protocol. During configuration in Studio 5000 Logix Designer, the user must define the Safety Network Number (SNN) and ownership to ensure that the safety data is securely and uniquely identified across the network.
Technical FAQ
Can the 1734-OB8S be used in a standard (non-safety) POINT I/O rack?
While it can physically fit in the rack, the 1734-OB8S requires a Safety Controller (like a GuardLogix) and a safety-rated communication adapter to function. It cannot be controlled by a standard non-safety PLC.
What is the maximum current I can draw at high temperatures?
At 55°C (131°F), the total module current is typically derated. While the maximum per point is 1.0A at 40°C, always consult the 1734-OB8S derating curves if your enclosure ambient temperature exceeds 45°C to prevent thermal shutdown.
Does this module support bipolar output wiring?
The 1734-OB8S provides sourcing outputs. For applications requiring dual-channel (bipolar) switching where one side is sourced and the other is sunk, you would typically pair this with a safety input or use specialized wiring configurations as defined in the Guard I/O safety manual.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
Understanding Root Causes of Unplanned PLC Stop Mode in Industrial Automation
Modern Programmable Logic Controllers manage execution through distinct operational states: Run, Stop, Start-Up, and Hold. During power-up, a controller initializes memory registers within Stop mode before briefly transitioning to Start-Up mode. During this phase, internal self-diagnostics evaluate system integrity across hardware and user programs. If the controller detects no critical faults, it enters Run mode to execute the control program continuously. However, any severe system anomaly forces the CPU back into Stop mode immediately to prevent erratic machine behavior across the plant floor.
Human-Machine Interface Design: Essential Guide to HMI Selection, Visualization, and Control System Integration
Human-Machine Interfaces (HMIs) serve as the primary operational window into complex industrial automation systems. Modern HMIs convert raw machine data into clear graphical displays, enabling operators to oversee entire manufacturing processes in real time. Instead of relying on physical control panels full of hardwired switches, engineers program interactive screens using intuitive graphics, dynamic color coding, and responsive touch interfaces. Over my 15 years in control systems engineering, I have observed HMIs transform from basic display screens into sophisticated command centers that drive operational efficiency across DCS and PLC environments.
Understanding Safety Relays in Industrial Automation: Architecture, Operation, and Functional Safety
Standard electromechanical relays provide basic electrical isolation between low-voltage control circuits and high-power output loads. A traditional switching relay features a magnetic coil driving mechanical Common (COM), Normally-Open (NO), and Normally-Closed (NC) contacts. However, standard relays pose severe functional risks when deployed in critical safety interlock circuits. High current inrush or mechanical wear can weld contacts together permanently. If contact welding occurs in an emergency stop circuit, pressing the button fails to halt hazardous machinery movements. Consequently, global functional safety standards prohibit standard relays for critical machine guarding functions.