The M12 D-coded connector is the 4-pole industrial Ethernet standard. It carries 100 Mbps for PROFINET, EtherNet/IP and EtherCAT, and it’s the connector you’ll find on almost every PLC, drive and field switch in a modern plant.
We stock D-coded connectors in male and female, straight and angled, shielded and unshielded, field-wireable and overmoulded. Panel-mount jacks with PCB tails are available for switch and device ports.
Key specifications
| Parameter | Value |
|---|---|
| Poles | 4 |
| Data rate | 100 Mbps (Cat5e) |
| Voltage / current | 250 V / 4 A |
| IP rating (mated) | IP67 |
| Cable OD | 6 – 8 mm |
| Standard | IEC 61076-2-101 |
Shielding is the decision that catches people out. If your cable run passes within a metre of a VFD or servo drive, use the shielded version – the foil and drain wire are what keep a PROFINET link from dropping packets when a motor starts. Unshielded works for quiet, short runs and saves a little cost.
PROFINET wiring note
The D-coded pinout is fixed: pairs on pins 1-2 and 3-4. When you terminate field-wireable versions, keep the untwist under 13 mm or you’ll degrade the signal beyond what the link can correct.
Frequently asked questions
Is D-coded the same as X-coded?
No. D-coded is 4-pole, 100 Mbps. X-coded is 8-pole, 10 Gbps. The shells both say M12 but they won’t mate across codes.
Do I need shielded for a 20 m PROFINET run?
20 m inside a panel with drives nearby – yes, use shielded. It’s the cheap way to avoid intermittent drops.
Field-wireable or overmoulded?
Field-wireable for one-off panel builds, overmoulded for repeatable production runs.
Quote M12 D-coded connectors – samples in 48 hours.