Industrial networking
M12 Ethernet to RJ45 Cables: D-Coded and X-Coded Options
Check the device port's coding and the performance it requires, then match the other end. D-coded and X-coded connectors do not share a key.
On this page
Look at the Ethernet port on the device before you look at a cable catalog. The port's coding, the performance the device requires, and the environment of the run decide the assembly. A cable with an M12 shell on one end and an RJ45 plug on the other can still be the wrong code. Sensor pinouts stay on the M12 sensor cable guide.
Check the Ethernet interface first
PI's PROFINET Design Guideline, order 8.062 version 1.38 from September 2019, describes a typical PROFINET copper cable as a 4-core shielded cable, and an 8-core cable for 1000 Mbit/s. It identifies the M12 D-coded connector with IEC 61076-2-101 and the M12 Type X connector with IEC 61076-2-109, the latter for higher transmission rates. The May 2023 PROFINET cabling guideline, order 2.252 version 5.3, still specifies both M12-D and M12-X connectors among the passive components. Coding is a mechanical key and a contact layout. It is not a guess you make from the number of sockets on a switch.
D-coded and X-coded assemblies
D-coded options
ifm's ecolink table describes D-coded M12 parts as data cables with 4 poles, typical limits under 30 V AC and 60 V DC, a maximum of 4 A, and CAT 5e. Those are ifm's typical figures for that coding in the ecolink range. The 2019 design guideline's 4-core shielded description is the same class of cable the D-coded connector serves in that document. A D-coded port needs a D-coded mate. An X-coded plug does not drop into it.
X-coded options
ifm describes X-coded parts, outside the main ecolink sensor set, as 8-pole data cables with typical limits under 50 V AC and 60 V DC, a maximum of 0.5 A, and CAT6. TE's M12 X-coded field-installable connector page states a Cat6A, 10 Gb/s connection, IP67 with an optional IP68, for wire sizes AWG 22, 24, and 26 and outer cable diameters from 6.0 mm to 9.0 mm. That page describes a field connector you install on a cable. binder's M12-X page describes 8-contact connectors, IP67, shielding, and molded cables, including M12 male to RJ45 male assemblies in a green PUR jacket, AWG 26/7, at listed lengths of 5 m and 10 m, plus M12-to-M12 cables. binder does not print a data rate on the listing reviewed here. Use TE's 10 Gb/s figure for that TE connector. Use binder's listing for the assembly construction it prints.
Supplier and assembly examples
The rows are examples with a public page, not a ranking and not a cross-reference that says any two of them mate.
| Example | Coding | Ends | Shield and jacket | Performance the page states |
|---|---|---|---|---|
| ifm ecolink D-coded summary | D, 4 poles | Family description, not one cordset. | Depends on the ifm series. | CAT 5e in the typical-data line. |
| ifm X-coded summary | X, 8 poles | Listed as further connection technology. | Depends on the item. | CAT6 in the typical-data line. |
| Phoenix Contact 1407495 | D, 4-position | Straight M12 plug to a free cable end. Length on this item is 1 m. | Shielded. PVC jacket, green RAL 6018. | PROFINET CAT5, 100 Mbps. The page cites cabling guideline version 2.00. The current PI download used here is version 5.3. |
| Phoenix Contact 1407472 | X, 8-position | Straight M12 plug to a straight RJ45 plug. Length on this item is 2 m. | Shielded. PUR halogen-free jacket, water blue RAL 5021. | Ethernet CAT6A, 10 Gbps. The page does not call this cable PROFINET. |
| L-com TRG610 category | X, 8-position | M12 male to RJ45. Listed lengths include 1, 2, 3, 5, and 10 m. | Double shielded. FR-TPE jacket. IP67 M12. | Category page: Category 6a and 10 gig speeds. Current and temperature were not on the opened SKU page. |
| binder series 876 M12 to RJ45 | X, 8 contacts | M12 male to RJ45, molded. Lengths printed include 5 m and 10 m. | Shielded. PUR jacket, green. AWG 26/7. IP67. | A bit rate is not printed on the listing reviewed. |
| TE M12 X-coded field connector | X | Field-installable connector for a cable you terminate. | Shielded metal shell. Cable OD 6.0 mm to 9.0 mm. | Cat6A, up to 10 Gb/s, IP67 or optional IP68. |
binder USA lists 3903 Calle Tecate, Camarillo, CA 93012 on the product page. That is the U.S. sales address on the page, not a manufacturing claim. TE's page does not name a plant.
What matters beyond the connectors?
Jacket, length, shield termination, and whether the cable will sit still or move all survive after the coding is right. binder's green PUR jacket is a published construction for those part listings. It is not a rule that every industrial Ethernet cable is green, and it does not state a flex or torsion rating. The sensor cable guide shows how a single Phoenix part publishes bend and torsion numbers. An Ethernet assembly needs the same kind of line if the route moves. The PROFINET buying guide is where fixed, flexible, and continuous-flex installations are separated.
How this relates to PROFINET and other networks
PROFINET uses Industrial Ethernet, and its cabling guideline specifies connectors that include M12-D and M12-X. A cable can be a shielded Ethernet assembly with those connectors and still lack the installation type or the documentation a PROFINET design asks for. Buying an X-coded patch cord does not, by itself, document a PROFINET cable type. Take that question to the PROFINET guide, with the device manual.
Questions before ordering
Can D-coded and X-coded cables be swapped?
The keys are different, and the contact counts on the pages above are 4 for ifm's D-coded summary and 8 for the X-coded products. They are specified under different IEC numbers in the PROFINET design guideline. Do not plan on mating them.
Which RJ45 cable is appropriate?
The one whose category and shield match the port, and whose other end is the coding on the device. binder's example is an 8-contact X-coded M12 molded to an RJ45. TE's example is a field X-coded connector you install on cable. A generic office patch cord is an RJ45-to-RJ45 lead. It does not terminate an M12 port.
What must be checked for a camera or a machine interface?
The port drawing: coding, whether the connector is male or female, the required category or bit rate, the shield, the IP rating if the port is outside a cabinet, and the motion of the cable. TE lists machinery, robotics, and industrial Ethernet switches among uses for its field connector. The machine builder's document still outranks that list.
Sources
Standards references are the PI documents linked below. Product rows use the manufacturer page named in the row. No pin assignment diagram was drawn, because none of these pages was used as a license to invent one.
- PROFINET Design Guideline, order 8.062, V1.38, September 2019
- PROFINET Cabling and Interconnection Technology, order 2.252, V5.3, May 2023
- ifm ecolink connection technology
- Phoenix Contact NBC-M12MSD, 1407495
- Phoenix Contact NBC-M12MSX, 1407472
- L-com M12 X-coded to RJ45 assemblies
- binder M12-X connectors
- TE Connectivity M12 X-coded field-installable connector