WIKA PSD-4-ECO Electronic Pressure Switch

Brand: WIKA (Germany). Full model designation: PSD-4-ECO. It belongs to the PSD series economical OEM programmable electronic pressure switch.

1. Product Profile

Designed for OEM mass equipment integration. It combines pressure measurement, digital display, switch outputs, analogue and IO-Link communication. Factory pre-configuration is available for direct installation upon delivery. Ideal for mass production of automation equipment, hydraulic stations, lubrication systems, cooling circuits, air compressors and other machinery. Cost advantage over the standard PSD-4 version.

2. Key Technical Specifications
3. Mechanical Structure & Display

Compact body with Φ29 mm outer diameter; display head rotatable through 335°, screen supports 180° electronic flip for easy reading in confined spaces.

4-digit LED display with tri-colour status indication: green when pressure is within set range; red for alarm / out-of-range condition. Local parameter configuration via 3 push-buttons.

2. Measurable Media: Non-hazardous gases and liquids (gauge pressure measurement).
3. Pressure Ranges: Vacuum from -1 bar up to 7500 psi (approx. 500 bar), multiple ranges available.
4. Accuracy: ≤ ±0.5% FS, low long-term drift.
5. Electrical Outputs (configurable options)

Two PNP/NPN switch points, independently configurable setpoint, reset point, hysteresis and delay; normally open / normally closed programmable.

Analogue output: 4–20 mA / 0–10 V; optional IO-Link 1.1 digital communication for pressure reading, diagnostics and remote parameterisation.

6. Environmental Resistance

Operating temperature: -40 ℃ ~ +125 ℃

Shock resistance: up to 50 g; switch service life ≥100 million switching cycles.

7. Power Supply: DC 10…30 V.
8. Pressure Process Connections: G1/4, 1/4 NPT and other thread options.
9. Model Nomenclature (PSD-4-ECO)

PSD: Pressure Switch Digital, electronic pressure switch with display

4: Product series

ECO: Economical OEM variant (bulk simplified packaging, factory pre-configuration for machinery OEM volume procurement)

Comparison: PSD-4 (Standard Version) with identical functions for project / spare part orders. PSD-4-ECO targets OEM mass orders with better pricing and factory preset parameters.

4. Typical Applications

Pressure monitoring and protection for hydraulic stations and lubrication systems

Pressure alarm for air compressors, refrigeration and cooling systems

Automation pressure control for construction machinery, packaging machines and machine tools

Water treatment and general industrial fluid monitoring

5. Installation & Commissioning Guidelines
6. Mounting: Avoid heavy vibration. Lock the rotating head after adjustment. Use PTFE tape for thread sealing on the pressure port. Do NOT torque the display housing.
7. Parameter setup: Local configuration via 3 push-buttons for switch threshold and hysteresis. IO-Link master enables remote parameter editing and device diagnostics.
8. Media limitation: Not suitable for strongly corrosive media. Medium temperature must not exceed sensor limits.
9. Troubleshooting Quick Reference

7. Alternative Selection Reference
8. Same brand upgrade: PSD-4 (standard version, better stock availability)
9. Domestic alternatives: Kangyu, Xingyi, Meikong digital pressure switches (lower cost, most without IO-Link)
10. Other imported brands: IFM PN series, SICK pressure transmitters with switch output

WIKA PSD-4-ECO Wiring Definition & IO-Link Register Description

Communication: IO-Link 1.1, COM2 (38.4 kbit/s), minimum cycle time 2.3 ms, Port Class A. IO-Link only available on PNP models; NPN versions do NOT support IO-Link.

Connector: M12×1, available as 4-pin (single switch) and 5-pin (dual switch + analogue) variants.

1. M12 Pin Assignment (Text-based Wiring Diagram)

1) 4-pin M12 (Single switch SP1, IO-Link optional)

2) 5-pin M12 (Dual switch SP1+SP2, analogue / IO-Link optional)

✅ IO-Link Wiring Key Points:

1. IO-Link uses pin 4 (C/Q), power via pin1 & pin3. No extra signal wire required.
2. Hardware multiplex of IO-Link and SP1. Device automatically switches to IO-Link mode when connected to IO-Link master.
3. Cable: Standard shielded IO-Link M12 cable, max. length 20 m.
4. Master port: Port Class A.

⚠️ Wiring Prohibitions:

No AC power input; avoid reverse polarity of U+/U-.

4–20 mA analogue is 3-wire; S+ must NOT be shorted to power.

PNP output: High level (~24V) when switched ON; NPN pulls to 0V when ON (NPN without IO-Link).

2. IO-Link Process Data (PD, Cyclic Real-Time Data)

Process data length: 4-byte input PD (Slave → Master); No output PD (Master cannot write cyclic process data).

Data format: Big-Endian, Float32 IEEE754. Pressure unit follows device internal setting (bar / MPa / psi).

Process data only transmits pressure value. Switch status, temperature and diagnostics are read via ISDU indexed parameters.

3. IO-Link ISDU Index Registers (Acyclic Read/Write, Master Parameter Access)

Index + Subindex. R=Read-only; RW=Read-Write

Device Information Area (Read-only)

Measurement & Diagnostic Read-only Parameters

System Command

4. IO-Link Commissioning Notes
5. IODD File: Download PSD-4-ECO IODD from WIKA official website. Import into IO-Link master software for automatic identification, no manual index entry required.
6. Power-up sequence: 1s boot time before IO-Link handshake.
7. Read/Write workflow:

Read live pressure: Read cyclic process data PD

Modify switch threshold: ISDU write 0xB0 (SP1 setpoint), 0xB1 (reset point)

Read switch status: ISDU read index 0x90, 0x91

4. Common IO-Link communication faults

Handshake failure: Check pin4 wiring; confirm PNP IO-Link version; verify supply voltage

Parameter write not effective: Some parameters require save command, others take effect immediately

Unstable pressure reading: Increase Signal Damping filter time

5. Normal Mode (Non-IO-Link) Wiring Summary

Without IO-Link master, pin4 of 4-pin /5-pin connector works as standard PNP SP1 output. SP2 is second switch output; S+ is 4–20mA /0–10V analogue output for direct connection to PLC analogue module.

WIKA PSD-4 Series Full Model Portfolio List

The PSD-4 series contains two main product lines: PSD-4 (Standard Industrial, PE81.86) and PSD-4-ECO (OEM Economy, PE81.69). Both are programmable electronic pressure switches with display, sharing similar hardware architecture, differing in temperature rating, packaging, pre-configuration capability and accuracy class.

This is a modular selection system. There is no fixed single part number. Complete order model is assembled by: [Base Model + Pressure Range + Output + IO-Link + Process Connection + Seal + Certificates].

1. Series Sub-families Overview

Note: Legacy PSD-30 is not part of PSD-4 series, it belongs to previous generation, avoid confusion.

2. PSD-4 Standard Version Available Ranges (Gauge G / Absolute A / Compound)

Gauge Pressure (G)

-1 … 0 bar (Vacuum)

-1 … +3 bar

0 … 0.4 bar

0 … 1 bar

0 … 2.5 bar

0 … 6 bar

0 … 10 bar

0 … 16 bar

0 … 25 bar

0 … 40 bar

0 … 60 bar

0 … 100 bar

0 … 160 bar

0 … 250 bar

0 … 400 bar

0 … 600 bar

Absolute Pressure (A)

0 … 0.4 bar abs

0 … 1 bar abs

0 … 2.5 bar abs

0 … 6 bar abs

0 … 10 bar abs

0 … 16 bar abs

0 … 25 bar abs

Compound Pressure (Vacuum + Positive)

-1 … +5 bar

-1 … +10 bar

-1 … +24 bar

3. PSD-4-ECO OEM Version Available Ranges

Range coverage is largely same as PSD-4. Max gauge pressure up to 0…1000 bar, high pressure ranges only available on ECO.

Vacuum: -1…0 bar; Compound: -1…+24 bar; Absolute max. 0…25 bar abs.

4. Output Options (Common for PSD-4 / PSD-4-ECO)
5. 1× switch output (SP1): PNP / NPN; M12 4-pin
6. 2× switch output (SP1+SP2): PNP / NPN; M12 4-pin
7. 2× switch + analogue: PNP/NPN + 4…20mA / 0…10V; M12 5-pin
8. IO-Link version: PNP with multiplexed C/Q; NPN hardware without IO-Link

IO-Link: 1.1, COM2; ECO strongly recommended for OEM IO-Link applications

5. Process Connection Options
6. G1/4 A male thread (ISO1179, most common)
7. G1/2 A male thread
8. 1/4 NPT male
9. 1/2 NPT male
10. Hygienic types: G1/2 B, Tri-clamp (PSD-4 standard only; PSD-4-ECO no hygienic diaphragm)
11. Seal Material Options

NBR (Nitrile): General water, compressed air, mineral oil, ambient temperature

FKM/Viton: Oil resistant, chemical & high temperature resistance

EPDM (EPDM): Hot water, dilute acid / alkali

7. Electrical Connection Options
8. M12×1 circular connector: 4-pin / 5-pin (mainstream)
9. Fixed angle cable outlet: 2m, 5m, 10m
10. Full Order Model Assembly Template

PSD-4 Standard Template

PSD-4 / Range / Output / IO-Link(Yes/No) / Process Connection / Seal / Certificate

Example:

PSD-4,0…10bar G,2×PNP+4-20mA,IO-Link,G1/4A,NBR,cULus

PSD-4-ECO OEM Template

PSD-4-ECO / Range / Output / IO-Link / Process Connection / Seal

Example:

PSD-4-ECO,-1…+24bar G,2×PNP,IO-Link,G1/4A,FKM

9. Pre-assembled Factory Reference Part Numbers (WIKA Article No.)

Reference only. Part numbers subject to revision. Place orders using model string above.

1. 14240381：PSD-4；-1…0bar G；Dual PNP switch, no analogue, M12 4-pin
2. 14240400：PSD-4；-1…+3bar G；Dual PNP switch
3. 14240463：PSD-4；-1…+3bar G；Dual PNP + 4-20mA analogue
4. 14240434：PSD-4；0…160bar G；Dual PNP switch
5. 14240494：PSD-4；0…160bar G；Dual PNP + 4-20mA analogue
6. PSD-4 vs PSD-4-ECO Core Comparison

11. Selection Notes
12. IO-Link is only available for PNP output variants. NPN hardware does not support IO-Link.
13. ECO is designed for OEM volume orders. Limited stock for single unit purchase. For project spares, PSD-4 standard is preferred.
14. All models support local 3-button configuration. IO-Link versions support remote read/write parameters. The IODD register definitions are largely identical for PSD-4 and PSD-4-ECO.
15. Explosion protection: Intrinsically safe versions are separate product lines outside PSD-4 family. PSD-4 / PSD-4-ECO are non-explosion-proof by default.