Omron NX-OD5256 Digital Output Module

Description

• Model breakdown​ (Omron NX-OD naming):
  • NX​ = NX series I/O module
  • OD​ = Output, transistor type (Digital Output transistor)
  • 5​ = 16 points (per Omron NX-OD family code)
  • 2​ = PNP (source-type) output
  • 5​ = Standard speed (0.5ms ON / 1.0ms OFF)
  • 6​ = 12mm wide, screwless push-in terminal block
  • → NX-OD5256 = NX series, 16-point, PNP 24VDC transistor output, standard speed, 12mm wide, push-in connector​

💡 “Standard speed” vs “High speed”: The NX-OD5256 is the standard-speed​ version (ON ≤0.5ms, OFF ≤1.0ms) . If your application needs ultra-fast switching (300ns ON/OFF), you’d need the NX-OD5156​ (high-speed variant) . For most machine control applications (solenoids, indicators, contactors, SSRs), the 0.5/1.0ms response of NX-OD5256 is more than adequate.

⚠️ PNP (Source-type) — NOT NPN!​ The NX-OD5256 is PNP source-type​ output . This means:

• The output terminal sources current​ to the load (load connects between output Y and 0V)
• Wiring: 24V+ → load → output Y → internal transistor → 0V
• If your system uses NPN sink-type​ sensors/loads → you need NX-OD5121​ (NPN equivalent of this module)
• Mixing PNP outputs with NPN-designed loads will NOT work correctly. Verify your existing system’s polarity before ordering.

⚠️ This is NOT a safety module!​ The NX-OD5256 does NOT support safety functions​ — no SIL rating per IEC 61508 . For safety-rated digital output (STO, SS1, etc.), you need Omron’s dedicated safety I/O modules (e.g., NX-SOD□). The NX-OD5256 is for standard machine control only.

Key Features​

• 16 PNP transistor outputs​ — DC24V rated, 0.5A per point, 4A per NX unit total
• Ultra-compact 12mm width​ — saves DIN rail space; up to 16 points in just 12mm of panel width
• Screwless push-in connector​ — detachable 16-terminal block, tool-free wiring, easy maintenance
• Short-circuit protection​ — each output point is individually short-circuit protected (auto-recovery when fault clears)
• Photocoupler isolation​ — galvanic isolation between I/O circuits (dielectric strength AC510V, 1 min)
• Standard speed response​ — ON ≤0.5ms, OFF ≤1.0ms — sufficient for most machine control
• Flexible I/O refresh​ — supports both free-running refresh​ and synchronous I/O refresh​ modes
• No external I/O power terminal​ — I/O power is supplied from the NX bus (backplane)
• IP20 protection, DIN rail mount, 0–55°C​ operating range
• Lightweight​ — only 70g
• Global certifications​ — CE, cULus, UKCA, RCM, KC, NK, LR, EAC, RoHS

Technical Specifications (NX-OD5256 — 16-pt DC24V PNP Transistor Output)

⚠️ Critical compatibility & selection notes:

1. Requires NX I/O bus infrastructure​ — The NX-OD5256 mounts on:
   • NX series CPU units​ (NX1P2, NX102, NX502, etc.) — direct backplane connection
   • NX-EtherCAT coupler units​ (NX1A-EN□, NX-ECC□) — for remote I/O over EtherCAT
   • NOT compatible​ with CJ, CS, or CP series PLCs (those use different I/O modules)
2. PNP only​ — If your loads are NPN (sinking) type, use NX-OD5121​ instead (NPN equivalent)
3. 12mm width, push-in connector​ — This specific model (-5256) is the 12mm wide, screwless push-in​ variant. If you need:
   • M3 screw terminal, 30mm wide​ → NX-OD5256-1​
   • MIL connector, 30mm wide​ → NX-OD5256-5​
   • 32-point version​ → NX-OD6256​ (PNP) or NX-OD6121​ (NPN)
4. 4A per NX unit limit​ — Total output current across all 16 points cannot exceed 4A. If you need more, either distribute across multiple NX-OD5256 modules or step up to NX-OD6256 (8A/unit)
5. No external I/O power terminal​ — The module draws I/O power from the NX backplane. Ensure your NX CPU/coupler has sufficient power budget (≤40mA consumption by this module)
6. Synchronous refresh requires Ver.1.1+ EtherCAT coupler​ — If you want to use time-stamp-based synchronous output, the connected EtherCAT coupler must be unit version 1.1 or higher, with Sysmac Studio version 1.07 or higher

NX-OD5256 Family Variants — Choose the Right One

Wiring Diagram (PNP Source-Type)

+24V DC ────┐
            ├───[Load 1]─── Y0 (NX-OD5256)
0V DC ──────┤
            ├───[Load 2]─── Y1
            ├─── ...
            └───[Load 16]── Y15

• V+ terminal: Connect to +24V DC (if external I/O power were used — but NX-OD5256 draws from NX bus)
• V- terminal: Connect to 0V DC (common)
• Y0–Y15: PNP output terminals — each sources current to the load when ON
• Internal common: All 16 outputs share an internal PNP common (no external COM terminal needed)

📌 Important: The NX-OD5256 has NO external I/O power terminal​ — I/O power is supplied from the NX backplane. You only connect your load wires to Y0–Y15 and the 0V reference. The 24V for the loads must be present in the system (either from the NX CPU’s internal supply or an external 24V PSU that also feeds the NX backplane).

Warranty & After-Sales

• Factory new units: 12 months warranty
• Refurbished units: 3-6 months warranty (bench: mount on NX CPU or EtherCAT coupler → Sysmac Studio auto-detect → force ON each output Y0–Y15 → verify 24V appears at output terminal with ≤1.5V drop → load 0.5A test load per point → verify short-circuit protection triggers and auto-recovers → confirm 4A total unit limit)
• Technical support for:
  • NX-OD5256 vs NX-OD5121 decision​ (PNP vs NPN — we verify your load polarity; most European/Asian machines use PNP, American machines often NPN)
  • NX I/O bus compatibility​ (verify your host: NX1P2/NX102/NX502 CPU or NX-EtherCAT coupler; we confirm unit version for synchronous refresh)
  • Terminal type selection​ (12mm push-in vs 30mm M3 screw vs 30mm MIL connector — based on your cabinet wiring preference and available DIN rail width)
  • Current budget calculation​ (0.5A/point, 4A/unit max — we help you size how many NX-OD5256 modules you need for your total output count)
  • Synchronous vs free-running refresh​ (for high-speed packaging/assembly, synchronous refresh with timestamp ensures deterministic output timing; requires EtherCAT coupler Ver.1.1+ and Sysmac Studio 1.07+)
  • Migration from older CJ/CS I/O​ (if upgrading from CJ1W-OD□ to NX-OD5256, wiring and program changes needed — we scope the migration)
  • Mixed NX-OD5256 + other NX modules​ (analog input NX-AD□, analog output NX-DA□, etc. — all on same NX backplane; we help configure the complete NX I/O stack)
• Optional: NX CPU unit (NX1P2/NX102/NX502), NX-EtherCAT coupler (NX1A-EN□), NX I/O power supply module, 24V DC power supply (for load side), DIN rail, Sysmac Studio software license, NX-OD5256-1 (M3 screw variant) or NX-OD5256-5 (MIL connector variant)

Delivery Time

• Standard delivery: 3-5 working days (stock NOS — NX-OD5256 is current production, generally available)
• Express shipping available upon request
• Note: Some distributors show long lead times from Omron Japan; we maintain NOS inventory for urgent replacement

Why Choose Our Store

• Genuine Omron NX-OD5256 — not gray-market (the push-in connector molding, photocoupler isolation ASIC, and short-circuit protection circuitry are factory-calibrated; clones fail I/O refresh, cause false short-circuit trips, and don’t seat properly on NX backplane)
• Global supply network with competitive pricing on full Omron NX I/O family (NX-OD□, NX-OC□, NX-ID□, NX-AD□, NX-DA□, NX-IA□, NX-MD□)
• Expertise in NX-OD5256 system (16-point PNP decode, 12mm push-in vs 30mm screw/MIL variants, PNP vs NPN selection, 4A/unit current budgeting, free-running vs synchronous refresh, NX CPU/coupler compatibility, migration from CJ/CS I/O, mixed NX module configuration)
• Comprehensive technical documentation (NX-OD5256 dimensional drawing, terminal layout, wiring diagram, NX backplane power budget guide, Sysmac Studio I/O configuration walkthrough, NX-OD family cross-reference, synchronous refresh setup guide)
• Responsive customer service and support

Applications

• NJ/NX Controller Digital Output Expansion: Primary application — NX-OD5256 adds 16 PNP 24VDC outputs to an Omron NX1P2, NX102, or NX502 CPU in just 12mm of DIN rail width. Perfect for controlling solenoid valves, indicator lamps, small relays, contactors, and solid-state relays (SSRs) in packaging machines, assembly cells, and material handling systems. The short-circuit protection on each point prevents a single faulty load from taking down the entire module.
• EtherCAT Remote I/O Node: When paired with an NX-EtherCAT coupler (NX1A-EN□), the NX-OD5256 becomes a remote I/O slice at the edge of the machine — e.g., a remote valve terminal 50m away from the main panel. The EtherCAT network brings deterministic I/O refresh; the NX-OD5256 provides the physical 16 PNP outputs locally. Up to 32 such slices can be daisy-chained on a single EtherCAT coupler .
• High-Density Panel Design: In compact control cabinets where DIN rail space is premium, the 12mm-wide NX-OD5256 packs 16 outputs into minimal width. A 200mm DIN rail section can accommodate 16+ NX modules, delivering hundreds of I/O points in a fraction of the space required by traditional 30mm+ I/O modules. Machine builders targeting IP67-rated compact panels (e.g., for food & beverage, pharmaceutical) rely heavily on NX-OD5256’s density.
• Packaging Machinery: On flow wrappers, cartoners, case packers, and palletizers — NX-OD5256 drives solenoid valves for pneumatic actuators, signals to servo drive enable inputs, indicator tower lamps, and alarm horns. The standard 0.5/1.0ms response handles typical machine cycle times (20–200ms per operation) without breaking a sweat. For ultra-high-speed labeling or registration marks, pair with NX-OD5156 (300ns) on the same NX backplane.
• Robotics & Assembly Cells: In a six-axis robot cell, the NX-OD5256 controls end-effector solenoids (gripper open/close), vacuum generators, indicator lights, and interlock relays. The synchronous I/O refresh mode (with appropriate EtherCAT coupler version) ensures output timing is precisely coordinated with robot motion — critical for high-precision pick-and-place.
• Semiconductor & Electronics Manufacturing: Wafer handling, die bonding, and SMT lines use NX-OD5256 for PNP control of vacuum valves, clamp cylinders, and status indicators. The short-circuit protection is vital in these environments where cable flexing and connector wear can cause intermittent shorts — the module auto-recovers when the fault clears, minimizing unplanned downtime.
• Legacy CJ/CS Migration: For factories upgrading from older Omron CJ1M/CS1 PLCs to NX series, the NX-OD5256 is the natural digital output replacement. While wiring changes are needed (CJ uses MIL connectors; NX uses push-in), the program conversion via Sysmac Studio is straightforward. The 12mm width and 16-point density mean fewer modules are needed compared to old CJ1W-OD201 (8-point, 31mm wide) — a typical 64-point output cabinet shrinks from 8 CJ modules (248mm) to 4 NX modules (48mm).
• Building Automation / HVAC: Large HVAC panels use NX-OD5256 for PNP control of damper actuators, pump contactors, fan starters, and status indicating LEDs. The 4A/unit capacity easily handles multiple small loads per module. DIN rail mount + IP20 + 0–55°C range suits electrical enclosure environments.