Omron Proximity Switch E2E-X2D1-N E2EX2D1N

Omron E2E-X2D1-N | Inductive Proximity Sensor — M8 Shielded, 2mm NO, DC 2-Wire, 10–30VDC, 1.5kHz, IP67, Oil-Resistant 2m Cable

Overview

The Omron E2E-X2D1-N is a shielded M8 inductive proximity sensor wired as a DC 2-wire normally open device, with a 2mm sensing distance and 1.5kHz switching frequency. The DC 2-wire circuit means just two wires — the sensor connects in series with the load between the DC positive supply and the return, requiring no separate power conductor. When a ferrous metal target enters the 2mm sensing field, the internal output circuit conducts and current flows through the load.

The appeal of DC 2-wire sensors lies in their installation simplicity. In a machine with many position-sensing points, eliminating the third (supply) wire from every sensor saves real cable cost, reduces connector pin count, and simplifies panel wiring.

The trade-off — a minimum load current of 3 mA and an off-state leakage of 0.8 mA — are manageable in most automation installations.

Standard 24V DC PLC input cards draw well above 3 mA in the ON state, and the 0.8 mA leakage falls well below the input's turn-on threshold, making the E2E-X2D1-N a straightforward drop-in for conventional machine sensor positions.

The stainless steel (SUS303) housing and oil-resistant PBT sensing surface are not incidental material choices.

In machine tool applications where the sensor spends its life surrounded by cutting coolant and oil mist, the housing must resist the chemical attack that corrodes conventional brass or zinc housings within months.

Combined with the IP67 + oil-proof sealing, the E2E-X2D1-N's material specification matches the actual chemical environment of machine tool installations where it is most commonly deployed.

Key Specifications

DC 2-Wire NO — The Series-Connection Circuit

In the DC 2-wire circuit, the sensor sits in series between the supply positive and the load. When no target is present (sensor OFF), the output transistor blocks — apart from the 0.8 mA leakage, no current flows through the load.

When the target is detected (sensor ON), the transistor conducts and current flows from supply through the sensor's output stage, through the load, and back to common.

Two practical implications follow directly from this circuit.

The minimum load current of 3 mA means the load must draw at least this much for the sensor's output to switch cleanly — very high-impedance loads or loads that draw less than 3 mA will produce unreliable or no switching. 

The 0.8 mA leakage must not exceed the connected PLC input's OFF-state threshold; if it does, the input reads continuously ON regardless of target presence. Standard industrial PLC inputs handle both of these constraints without issue: their minimum ON current exceeds 3 mA and their OFF threshold comfortably ignores 0.8 mA.

The "with polarity" designation means the two sensor wires have defined positive and negative roles — they are not interchangeable. Reversing the wires at installation prevents normal operation; however, the surge suppressor within the E2E-X2D1-N's protection circuit prevents permanent damage from brief polarity reversal, allowing the wiring error to be corrected without sensor replacement.

1.5kHz Response — Mid-Speed Detection Capability

At 1.5kHz, the E2E-X2D1-N completes 1,500 full detection cycles per second. For presence/absence detection on conveyors, end-of-travel position confirmation on cylinders, and part-in-fixture checks in assembly stations, this response speed is comfortably faster than any mechanical event the sensor needs to track.

For applications requiring pulse counting from rapidly rotating gear teeth or encoder discs, 1.5kHz imposes a practical limit: reliable counting requires that each target event occupies at least one full switching period, which at 1.5kHz means target-passing rates up to approximately 750 events per second can be resolved cleanly.

Shielded Flush Mounting — Maximum Installation Flexibility

Shielded construction focuses the electromagnetic field forward from the sensing face, preventing lateral field extension that would be absorbed by surrounding metal in a flush-mount installation. The E2E-X2D1-N threads into standard M8 × 1mm mounting holes and is secured with the supplied M8 lock nuts, with the sensor face flush to or recessed into the surrounding metal bracket. This protects the sensing face from direct mechanical contact in applications where targets approach from the side or where the installation space is confined.

FAQ

Q1: How does the E2E-X2D1-N (NO) differ from the E2E-X2D2-N (NC) version?

The two sensors are electrically identical in construction, housing, and sensing distance. The difference is output state when no target is present: the D1 variant (NO) has its output transistor OFF (circuit open) when idle and ON when target is detected; the D2 variant (NC) is the opposite — output is conducting when idle and opens when target is detected. Choose NO for standard presence-detection interlocks where "target present = circuit active"; choose NC for fail-safe applications or reverse-logic circuits where "target absent = circuit active."

Q2: The leakage current is 0.8 mA — will this cause a false output on my PLC input?

For the vast majority of industrial PLC input cards, 0.8 mA is well below the minimum ON-state current threshold (typically 2–5 mA).

The input remains in the OFF state when 0.8 mA flows through it with no target present.

If using an unusually sensitive input with a very low ON threshold, a bypass resistor (5.6 kΩ to 10 kΩ) connected in parallel with the PLC input will shunt the leakage current and prevent any false activation.

Q3: The standard sensing object is iron 12 × 12 × 1 mm — what happens with smaller targets?

The 2mm sensing distance is characterised for the 12 × 12 × 1mm iron test plate. Smaller target areas return less electromagnetic flux to the sensor coil and produce shorter effective sensing distances.

For M8 sensors, the target area should ideally equal or exceed the sensor face area (approximately 8mm diameter circle). A 6 × 6mm iron target produces approximately 85% of the rated distance; a 4 × 4mm target, approximately 70%.

Always measure the actual switching point with the specific target dimensions in the installation conditions before fixing the mechanical mounting position.

Q4: Can the E2E-X2D1-N operate on a 12V DC supply?

Yes. The operating voltage range is 10–30V DC, which covers both 12V and 24V DC supplies.

At 12V supply, the sensor's output transistor residual voltage reduces the effective load voltage — ensure the load operates reliably at this reduced voltage. 

For PLC input cards specifically rated for 24V input, verify that the reduced supply voltage still meets the input's minimum ON-state voltage requirement at the input terminal after accounting for cable drop and the sensor's residual voltage.

Q5: The IP rating is IP67 plus "oil-proof" — what does the oil-proof designation add?

IP67 covers dust ingress protection (complete exclusion) and temporary water immersion (1m, 30 minutes). Omron's "oil-proof" company standard extends the sealing validation to cutting oils, hydraulic oils, and metalworking coolants — fluids that are chemically different from water and attack seal materials differently.

The stainless steel housing and PBT sensing surface, combined with the oil-proof sealing, qualify the E2E-X2D1-N for machine tool environments where sustained oil exposure is the normal condition throughout the sensor's service life.