FX2N-16EX-ES/UL Genuine Mitsubishi FX2N16EYRESUL PLC Module

That single letter — X vs Y — is the entire difference between an input module and an output module. FX2N-16EX = 16 inputs. FX2N-16EYR = 16 relay outputs. FX2N-16EYT = 16 transistor outputs. Keep this in mind when reading wiring drawings or comparing quotes from different suppliers.

Technical Specifications

Input Wiring: Sink vs Source — Which Does the FX2N-16EX Support?

The FX2N-16EX-ES/UL uses sink input wiring (NPN) as its default configuration. In sink input mode, the input circuit is completed when the sensor or switch connects the input terminal to 0V (COM). This matches the standard NPN (negative switching) output of most proximity sensors, photoelectric sensors, and limit switches used in Japanese and Asian-market machinery — which is exactly the installed base most FX2N systems live in.

For European and American machinery that uses PNP (positive switching, source output) sensors, the FX2N-16EX-ES/UL can also be wired in source mode by reconfiguring the internal S/S terminal connection. In source mode, the input is activated by connecting the terminal to 24V DC rather than 0V. The module's terminal block includes both S/S and COM terminals specifically to accommodate both wiring styles. Check the Mitsubishi FX2N Hardware Manual (JY992D88201) for the exact terminal configuration diagram for source wiring.

How X Addresses Are Assigned

When you plug the FX2N-16EX-ES/UL into the extension bus, the PLC automatically assigns X input addresses in sequence — no hardware switches, no parameter changes in GX Works. The CPU counts from the base unit's last native input and assigns the next available X addresses to the extension module.

A quick example: the popular FX2N-32MR base unit has 16 native inputs (X0–X17 in octal notation) and 16 native outputs (Y0–Y17). Add one FX2N-16EX-ES/UL to the right, and it takes X20–X37. Add a second FX2N-16EX-ES/UL to the right of that, and it takes X40–X57.

Two things to keep in mind here. First, Mitsubishi FX uses octal numbering for I/O addresses — there is no X8, X9, X18, X19, etc. This is a common source of off-by-one errors when writing ladder programs. Second, any output modules (FX2N-16EYR, FX2N-16EYT) installed between input modules on the bus do not consume X addresses — inputs and outputs are counted separately.

FX2N Input Module Selection at a Glance

The FX2N-8EX works well when you only need a few extra inputs and panel space is tight. The FX2N-32EX makes sense when you need a lot of inputs and want to minimize the number of modules on the bus. For most standard applications where 16 inputs covers the gap, the FX2N-16EX-ES/UL is the natural choice.

Real-World Applications

Production line sensor expansion — a packaging machine running an FX2N-48MR with all 24 native inputs occupied by product-present sensors, safety gate switches, and cam position sensors. Adding an FX2N-16EX-ES/UL accommodates 16 more sensors without hardware redesign or CPU replacement.

Multi-station assembly fixtures — each station has multiple part-present confirmation sensors, clamp confirmation switches, and tooling seated signals. As stations are added to an existing FX2N-controlled system, input extension modules scale the I/O count without replacing the CPU.

Machine retrofits with additional safety interlocks — older machines with FX2N PLCs being updated to include additional safety interlock sensors (e.g., additional guard monitoring, new emergency stop circuits feeding PLC monitoring inputs) where the original I/O count was not designed for the expanded sensor set.

Agricultural and food processing equipment — level sensors, flow switches, and proximity sensors across multiple process zones on irrigation controllers and filling machines where the FX2N's proven reliability and the 16EX's UL certification support both North American and international market requirements.

Laboratory test automation — instrument trigger inputs, limit switch arrays on multi-axis positioning stages, and pass/fail sensor inputs on automated test equipment built around FX2N or FX3U controllers.

Connecting the Module: It Really Is This Simple

Unlike special function modules (analog, temperature, high-speed counter), the FX2N-16EX-ES/UL requires zero configuration. The installation process:

1. Power down the FX system completely
2. Remove the right-side cover from the last module in the current chain
3. Click the FX2N-16EX-ES/UL into position — the bus connector engages mechanically and electrically
4. Power on
5. The CPU immediately recognizes the new input points at the next available X addresses
6. Wire your sensors to the input terminals and COM

That's it. No STEP 7, no GX Works parameter download, no address DIP switches. The only thing to do in software is make sure your ladder program references the correct X addresses — which you can confirm in one second with GX Works2/3 online monitoring.

Procurement & Shipping

• 🔒 Genuine Mitsubishi Electric — factory sealed with matching labels and UL markings
• ✅ New original — not refurbished, not pulled from equipment, not repackaged surplus
• 📋 ES (IEC/CE) and UL/cUL certified — suitable for both North American and international machine compliance
• 📦 Original Mitsubishi factory packaging
• 🌍 Worldwide express shipping (DHL / FedEx / UPS)
• ⚡ In stock — dispatches within 1–2 business days

❓ FAQ — Mitsubishi FX2N-16EX-ES/UL Input Extension Module

Q1: Does the FX2N-16EX-ES/UL have any outputs, or is it inputs only?

 It is inputs only — all 16 points are digital inputs. There are no output circuits on this module at all. The "EX" in the part number means Extension Input: E for extension, X for input. If you need output expansion, you're looking at the FX2N-16EYR-ES/UL (relay outputs) or FX2N-16EYT-ESS/UL (transistor outputs) — completely different modules. This is worth double-checking before ordering because the modules look similar externally and the part numbers are easy to confuse in written BOMs and purchase orders.

Q2: Will this module work with an FX3U PLC, or only FX2N?

The FX2N-16EX-ES/UL is fully compatible with FX3U base units and connects directly to the FX3U's right-side extension bus. It works alongside FX3U-native extension modules without any compatibility issues, and the FX3U CPU handles X address assignment the same way as an FX2N — automatically and sequentially. For FX2NC and FX3UC (compact versions with a smaller bus connector format), a bus conversion adapter is required. The module is not compatible with the older FX0N, FX1S, or FX1N product families.

Q3: My sensors are PNP (sourcing) type — can I still use this module?

Yes, with a wiring change. The FX2N-16EX-ES/UL supports both NPN (sink) and PNP (source) sensor wiring via the S/S terminal on its terminal block. For NPN sensors: connect S/S to 0V (COM) — sensor output connects to the input terminal and pulls it low to activate. For PNP sensors: connect S/S to 24V DC — sensor output connects to the input terminal and pulls it high to activate. The hardware is the same either way; it's purely a wiring configuration difference. Refer to the FX2N Hardware Manual for the precise terminal diagram, and note that you cannot mix NPN and PNP sensors on the same module — the S/S setting applies to all 16 inputs simultaneously.

Q4: How do I find out which X addresses this module will be assigned in my system?

The addresses are assigned automatically in sequence from left to right across the extension bus, starting from the next available X address after the base unit's last native input. To determine the starting address: count the native input points on your base unit (e.g., FX2N-32MR has 16 inputs → X0–X17 in octal), then count any input extension modules already connected to the right. The first FX2N-16EX added after an FX2N-32MR takes X20–X37; a second takes X40–X57; and so on. Remember that FX address numbering is octal — X7 is followed by X10, not X8. Output modules on the bus do not affect input address counting.

Q5: Does adding this module require any changes to the GX Works2 program or hardware configuration?

No parameter changes or hardware configuration downloads are needed for the FX2N-16EX-ES/UL. The FX2N and FX3U CPUs scan the extension bus automatically at power-up and recognize connected modules. The new X input addresses become immediately available in the PLC program without any software configuration. You do need to update your ladder program to add the contact logic referencing the new X addresses — but the module itself needs nothing configured. This is in contrast to special function modules (like the FX2N-4AD-PT), which require explicit FROM/TO instructions in the program to access their buffer memory.

Q6: What is the input response time, and can it be changed?

The default input response time is 10ms — this is a digital filter built into the input circuit that prevents false triggering from contact bounce and electrical noise. For most general-purpose inputs (pushbuttons, limit switches, proximity sensors at normal machine speeds), 10ms is perfectly adequate. On FX3U systems, the input filter time for the first 8 inputs (X0–X7) can be adjusted in the PLC parameters down to 0ms (unfiltered) or up to 60ms, useful when those inputs are used for high-speed counting or when additional filtering is needed in noisy environments. On FX2N systems, the filter time is fixed at 10ms and cannot be adjusted via parameters. Note that the adjustable filter only applies to the base unit's built-in high-speed inputs — the extension module inputs on FX2N are fixed at 10ms regardless.

Q7: How many FX2N-16EX-ES/UL modules can I connect to a single FX2N system?

The FX2N supports a maximum of 256 I/O points total across the base unit and all extension modules combined, and a maximum of 8 extension modules on the right-side bus (input and output modules counted together). In practice, a fully loaded system with an FX2N-32MR (16 in + 16 out) and eight FX2N-16EX modules would have 16 + 128 = 144 input points and 16 output points — well within the 256-point limit. Before adding modules, also verify the extension bus power budget: each FX2N-16EX-ES/UL draws approximately 50mA from the 5VDC extension bus, and the FX2N base unit has a maximum extension bus current capacity (typically 460mA for standard CPUs). Exceeding this causes intermittent module communication errors that can be difficult to diagnose.