Which connectors does M12 IO-Link Cable use?

One end is M12 A-coded, 3, 4 or 5 pins, straight or right-angle and the other end is M12 A-coded or open leads.

What ingress protection does M12 IO-Link Cable have?

Sealing is rated IP67 when mated - confirm per build.

M12 IO-Link Cable, Master to Device Drop Cordset

Last updated: 13 September 2026

Overview

An M12 IO-Link cable looks like an ordinary sensor cordset, and in most cases that is exactly what it is. IO-Link is deliberately simple at the physical layer: one master port talks to one device over three or four conductors that carry the supply and the switched signal together. That is why the cable is unremarkable and the specification is not – the same pair carries 24 V and the communication signal, so conductor size, contact quality and drop length decide whether a device stays online.

Key Specifications

Coding	A-code, sensor and actuator
Connector A	M12 A-coded, 3, 4 or 5 pins, straight or right-angle
Connector B	M12 A-coded, or open leads
Wiring	3-wire or 4-wire, port class A or port class B
Supply	24 V DC sensor supply – confirm per build
Conductor size	Sized to the drop length – state the run
Jacket	PUR for washdown and coolant, PVC for dry panels
Shielding	Unshielded as standard; shielded option for heavy EMC areas
Ingress rating	IP67 when mated – confirm per build

The cable is ordinary. The drop is not.

IO-Link is a point-to-point link rather than a bus: one master port talks to one device over three or four conductors. Because the supply and the signal share conductors, anything that drops voltage at the far end shows up as a communication fault rather than as a power fault. Undersized cores let the device brown out and re-enumerate. A marginal crimp does the same intermittently, which is far harder to diagnose than a hard break. On a long drop the conductor choice matters more than the protocol does, and that is the number we ask for first.

Port class A and port class B pinout reference

The difference between the two port classes is whether the port offers a second supply pair for higher-power devices. On a class A port pins 2 and 5 are not used; on a class B port they carry the additional supply. Get this wrong and an actuator will not move even though the link associates correctly.

Pin	Port class A	Port class B	Typical color	Note
1	L+ (24 V)	L+ (24 V)	Brown	Device and communication supply
2	Not connected	P24 – additional supply +24 V	White	Present on class B ports only
3	L- (0 V)	L- (0 V)	Blue	Return
4	C/Q – communication and switching	C/Q – communication and switching	Black	The signal contact; the one that decides link quality
5	Not connected	P0V – additional supply 0 V	Gray	Present on class B ports only

We terminate to the pinout you send. Where a machine mixes class A and class B devices, tell us and we will suggest a jacket color or a printed legend so the two are not swapped during maintenance.

Where IO-Link sits in the M12 coding family

IO-Link runs on the general-purpose A-code, the same keyway as an ordinary sensor cordset. Everything else in the family is keyed for a different job – fieldbus, Ethernet, AC power, DC power or a hybrid. The map below is what each coding is for and how many positions it normally uses.

Code	Positions	Carries	Typical use
A	3 / 4 / 5 / 8 / 12	DC sensor supply and signals, IO-Link	Proximity switches, photoelectric sensors, valve plugs
B	5	PROFIBUS-DP fieldbus	Legacy drives, remote I/O racks, weigh scales
C	3 to 6	AC power, dual keyway, extended earth	AC sensors, solenoid coils, legacy actuator blocks
D	4	100 Mbit/s Ethernet over two pairs	PROFINET, EtherNet/IP, EtherCAT device drops
K	4 + PE	Three-phase AC power	Motor feeds, power distribution blocks
L	4 + PE	DC power	IO-Link power, AGV and drive supplies
M	5 + PE	Three-phase motor plus brake pair	Servo and geared motors with holding brake
P	4 + PE	Data pairs plus 24 V DC supply	Single-cable EtherCAT and remote I/O blocks
S	3 + PE	Single-phase AC power	Field I/O blocks, cabinet heaters, pumps, fans
T	4	DC power, two circuits	Low-voltage DC distribution
X	8	Up to 10 Gbit/s Ethernet over four pairs	Machine vision, M12 to RJ45 10G links
Y	6 + PE / 8	Hybrid power plus Fast Ethernet	Valve islands, hybrid power and data drops

A, B, C and D are set out in IEC 61076-2-101, X in IEC 61076-2-109 and the power codings in IEC 61076-2-111. Y is a de-facto hybrid arrangement rather than an IEC-defined code. These are the industry-standard descriptions of purpose; the current and voltage figures your assembly is built and verified to are the ones stated on your drawing.

Drop length, conductor size and what we check

Drop condition	What we check	What changes in the build
Short drop in a cabinet or on a nearby manifold	Standard cordset is adequate	Default conductor size, unshielded
Medium run across a machine	Voltage at the device under load	Step up one conductor size
Long run to a remote device	Voltage drop and re-enumeration margin	Larger cores, or move the master closer
Run past drives or weld equipment	EMC environment	Shielded build with the braid bonded to the coupling nut

IO-Link itself is covered by IEC 61131-9 as an industry standard, and the description here is the general one – your assembly is built and verified to the values on your drawing, not to a catalog number. Tell us the actual run and we size the conductors so the device still sees a healthy supply at the far end.

How we build these

A-coded M12 heads in straight or right-angle form, male or female, molded in volume
PVC for dry panels, PUR for washdown, coolant and oil mist
Overmold formed onto the jacket so the strain relief and the seal are one piece
Continuity and pull testing at the connector before the drop leaves the bench

Typical applications for this M12 IO-Link cable

Sensor drops from an IO-Link master to proximity, pressure and level devices
Valve terminals and manifold blocks on packaging machines
Smart actuator drops where the link carries both data and supply
Power for the master itself, using our M12 L-code 16 A cable for IO-Link power
Split supplies across two masters with our M12 L-code power splitter
Hybrid power and data to valve islands using our M12 Hybrid SPE cable

What we need from you

Port class – A or B – and the pin count
Drop length, measured rather than estimated
Device current draw
Straight or right-angle, and on which end
Jacket exposure – washdown, coolant, oil, outdoor UV
Whether shielding is required

Workmanship and testing

Cable assemblies here are built to IPC/WHMA-A-620 Class 3 workmanship inside an ISO 9001 system, across a 32 to 12 AWG range. Continuity and pinout are verified on every unit before packing. Seal checking on the batch can be quoted when an ingress rating is specified.

Custom builds and ordering

A prototype lot of 5 pcs ships in 3 working days; series orders start at 500 pcs and ship 14 working days after sample approval. We hold 100 sets of mold tooling in house, so a standard body needs no tooling time and a new one adds about 10 working days. OEM and ODM builds go out under your part number and label, with material certificates and first-article reports on request.

Related IO-Link and M12 assemblies

Full range: Circular M8 and M12 cable assemblies.

Frequently Asked Questions

Is an IO-Link cable just a sensor cable?

Physically yes, in most installations. The specification is what differs: conductor size and drop length matter more, because the supply and the signal share the same conductors.