SIEMENS 6ES7321-1BH50-0AA0 Digital Input Module – SIMATIC S7-300 Series
Imagine a critical production line suddenly going blind — sensors firing, limit switches tripping, emergency stops triggering — but the PLC receives nothing. No signal. No response. The entire automated sequence halts, operators scramble, and every minute of downtime translates directly into lost revenue and potential safety incidents. This is the reality when a digital input module fails or is missing from your SIMATIC S7-300 control system. The SIEMENS 6ES7321-1BH50-0AA0 is the precise component that bridges the physical world of field devices and the logical world of your PLC program — without it, your automation system is deaf to its environment.
The 6ES7321-1BH50-0AA0, also designated as SM 321, is a 16-channel 24 VDC digital input module engineered for the SIMATIC S7-300 modular PLC platform — one of the most widely deployed programmable logic controller families in global industrial automation history. Within the SM 321 sub-family, this module occupies the high-density, cost-efficient tier, offering 16 isolated digital inputs in a compact S7-300 form factor. It is trusted by system integrators and OEMs across automotive manufacturing, process industries, material handling, and building automation worldwide.
Technical Specifications
- Part Number: 6ES7321-1BH50-0AA0
- Module Designation: SM 321 Digital Input Module
- Series: SIMATIC S7-300
- Number of Inputs: 16 digital inputs
- Input Voltage: 24 VDC
- Input Type: Sink/Source (IEC Type 1/Type 2 compatible)
- Isolation: Galvanic isolation between channels and backplane bus
- Backplane Bus Interface: S7-300 standard backplane connector
- Dimensions (W×H×D): 40 mm × 125 mm × 120 mm (standard S7-300 module)
- Operating Temperature: 0 °C to +60 °C
- Storage Temperature: −40 °C to +70 °C
- Degree of Protection: IP20
- Approvals: CE, UL, cULus, FM, ATEX (refer to datasheet for full certification list)
- Weight: Approx. 200 g
Note: All specifications are sourced from official SIEMENS documentation. Always verify against the current product datasheet for your specific application.
Key Features & Benefits
- 16 High-Density Digital Inputs: Maximizes I/O density per rack slot, reducing hardware footprint and cabinet space requirements.
- 24 VDC Standard Voltage: Compatible with the vast majority of industrial field devices, sensors, and switches used in global automation projects.
- Galvanic Isolation: Protects the CPU and backplane bus from electrical noise, ground loops, and transient surges originating in the field wiring.
- Plug-and-Play S7-300 Integration: Slots directly into any S7-300 rack without additional configuration hardware — recognized automatically by STEP 7 and TIA Portal.
- Diagnostic Capability: Supports module-level diagnostics accessible via STEP 7 / TIA Portal for rapid fault identification during commissioning and maintenance.
- Wide Operating Temperature Range: Suitable for demanding industrial environments from controlled clean rooms to harsh factory floors.
- Long-Term Availability: As a proven S7-300 component, replacement modules and spare parts remain available through authorized distributors and specialist suppliers like Konmask.com.
Industry & Equipment Applications
- Automotive Manufacturing: Body-in-white assembly lines, welding stations, conveyor interlocks, and end-of-line test rigs.
- Process Industry: Chemical plants, water treatment facilities, oil & gas upstream/downstream control panels.
- Material Handling & Logistics: Sorting systems, palletizers, automated storage and retrieval systems (AS/RS).
- Food & Beverage: Filling lines, packaging machines, CIP (Clean-In-Place) control systems.
- Building Automation: HVAC control panels, fire and gas detection integration, access control systems.
- Machine Tool & OEM Equipment: CNC machine tool auxiliary I/O, injection molding machines, press control systems.
System Integration & Compatible Parts
The 6ES7321-1BH50-0AA0 is designed to operate within the SIMATIC S7-300 ecosystem. Compatible and commonly paired components include:
- CPUs: S7-300 CPU family (e.g., CPU 314, CPU 315-2 DP, CPU 317-2 PN/DP)
- Power Supplies: PS 307 series (6ES7307-xxxx-0AA0)
- Racks: UR1, UR2 universal racks (6ES7390-1xxxx-0AA0)
- Digital Output Modules: SM 322 series (e.g., 6ES7322-1BH01-0AA0)
- Analog Modules: SM 331 / SM 332 series for mixed I/O configurations
- Front Connectors: 6ES7392-1AJ00-0AA0 (20-pin front connector, sold separately)
- Programming Software: SIEMENS STEP 7 V5.x or TIA Portal V13 and above
Our Quality Assurance Process
At Konmask.com, every SIEMENS module we supply undergoes a rigorous multi-stage verification process before shipment:
- Authenticity Verification: Physical inspection of labeling, firmware version markings, and holographic seals against known-genuine references.
- Functional Testing: Where applicable, modules are bench-tested to confirm basic I/O response and communication integrity.
- Condition Grading: Products are clearly graded as New (factory-sealed), Refurbished (tested & restored), or Used (tested, cosmetic wear acceptable) — you always know exactly what you receive.
- Secure Packaging: Anti-static packaging with moisture barrier bags and foam cushioning to prevent transit damage.
- Traceability: Each order is documented with batch records for full supply chain traceability.
How to Order
- Confirm the part number: 6ES7321-1BH50-0AA0
- Specify required quantity and preferred condition grade (New / Refurbished / Used).
- Submit your inquiry via the Contact Us form or email support@konmask.com.
- Receive a formal quotation with lead time, shipping options, and payment terms within 24 business hours.
- Confirm order and receive tracking information upon dispatch.
For urgent requirements or large-volume procurement, please call us directly at +0086 19859288691.
Why Choose Konmask.com?
- ✅ Specialist Focus: We exclusively handle industrial automation components — PLC modules, DCS parts, drives, and HMI hardware.
- ✅ Global Sourcing Network: Access to both new and hard-to-find legacy SIEMENS S7-300 components through our verified supplier network.
- ✅ Technical Expertise: Our team includes experienced automation engineers who can assist with compatibility verification and system integration questions.
- ✅ Fast Worldwide Shipping: Partnerships with major international freight carriers ensure reliable delivery to Europe, Americas, Southeast Asia, and beyond.
- ✅ Responsive Support: Dedicated B2B account management with rapid response to RFQs and technical inquiries.
- ✅ Competitive Pricing: Direct sourcing relationships allow us to offer market-competitive pricing on both standard and obsolete parts.
Frequently Asked Questions
Q: Is the 6ES7321-1BH50-0AA0 compatible with TIA Portal?
A: Yes. The SM 321 module is supported in TIA Portal (V13 and above) as well as the classic STEP 7 V5.x environment. Hardware configuration is straightforward using the standard S7-300 hardware catalog.
Q: What is the difference between 6ES7321-1BH50-0AA0 and 6ES7321-1BH02-0AA0?
A: Both are 16-channel 24 VDC digital input modules for S7-300, but they differ in hardware revision and minor feature updates. The -1BH50 revision incorporates updated internal circuitry. Always verify compatibility with your specific CPU firmware version before substitution.
Q: Can this module be used in a PROFIBUS DP distributed I/O configuration?
A: The 6ES7321-1BH50-0AA0 is a centralized S7-300 rack-mounted module. For distributed PROFIBUS DP I/O, consider the ET 200M or ET 200S product families with equivalent SM 321 modules.
Q: Do you provide a warranty on this module?
A: Yes. All modules supplied by Konmask.com carry a warranty against defects. Warranty period and terms vary by condition grade — please confirm at time of quotation.
Q: How long does shipping take?
A: Standard international shipping typically takes 5–10 business days depending on destination. Express options (DHL, FedEx, UPS) are available for urgent requirements.
Q: Can you supply multiple units for a plant-wide spare parts program?
A: Absolutely. We regularly fulfill bulk orders for MRO spare parts programs. Contact us for volume pricing and scheduled delivery arrangements.
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Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
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