M12 Factory Automation Cables, Coding Explained

M12 connectors are circular connectors with a 12 mm locking thread and have become the standard for use in factory automation applications, they come in many different shapes and sizes, when you select a cable it is important to choose the right length, the correct number of pins, jacket material, and just as importantly the right coding for the application.

There are many different types of coding for instrumentation cables, but why are they coded, what are they all for and where should they be used?

Each code is used for a specific application, the coding indicates different keyways to ensure that connectors mate / cables connect with those that they’re intended to, and prevent the opposite, for example, ensuring an AC power cable is never mated with an ethernet cable.

From the outside, connector housings look the same but there are many different and diverse internal configurations.

Most users of M12 cables are familiar with codes A through D and possibly X.

A Code

A-code (also known as Micro-DC) is the most widely used coding in factory automation applications of all the types. These connectors are used in data applications primarily involving DC power.  A-coding is used for attaching actuators, attenuators, sensors, AI-vision systems, motor-operated switches and other devices. A-coded connections are also used to transfer up to 1-Gbit of data in Ethernet applications and can have anywhere from 2 to 17 pin positions.

B Code

B-code is unique in that it contains a reversed single keyway, which allows 2 unique M12 connections to be mounted on the same panel without the risk of incorrectly coupling connections to equipment with varying voltage and amperage.  B-coding is used in fieldbus connections involving Profibus and Interbus. B-coding connectors typically have anywhere from 3 to 5 pins.

C Code

C-code (also known as Micro-AC) is strictly used in cases where AC current is involved, such as with AC actuators, sensors and other AC devices, it is not as commonly used as the other types. Connections with C-coding all have extended grounding pins and double keyways for added safety, to prevent them from being mistaken for other similar-looking connections and being coupled with the wrong cables. C-coding connections have anywhere from 3 to 6 pins.

D Code

D-code is specifically used in network cables for industrial Ethernet applications to transfer data up to 100-Mbits. The insides of cables with this type of coding consist of either 4 wire connectors (D-coding) with 2 pairs of Cat 5e cables or M12 8 wire (A-coding) connectors with 4 pairs of Cat 5e cable.

D-coding can also be used with Profinet, Ethernet/IP and EtherCat systems. D-coded connections usually have 3 to 5 pins.

X Code

X-code has been introduced more recently and is quickly becoming a standard for use with high-speed industrial Ethernet applications. X-coding has is able to transfer large amounts of data at high speeds, up to 10-Gbits of data.  X-coding is expected to eventually replace A and D coded parts for Ethernet applications.  X-coding applications include high-speed industrial Ethernet and Cat6A, this code always has 8 pins.

New Codes

There are more codes in addition to these and some have been designed to replace existing codes.

These include L, S and T for Power applications, and P code for applications requiring quick connect / disconnect.

Mueller M12 Cables

Mueller Electric’s M12 instrumentation cables include one of the most reliable and efficient connection standards for industrial machinery and industrial automation applications. With a small footprint, high-performance capabilities and extremely low failure rate, this range is ideal for not only for sensor connections but also for various fieldbus systems.

With a high degree of mechanical and electrical stability, Mueller M12 cables provide a cost efficient and flexible plug-and-play connectivity solution for onsite installations. This decreases downtime in process control and industrial automation applications. Features include:

  • Industry-standard screw-locking mechanism
  • IP67 or higher degree of protection
  • A, B, C, D & X-Coding options
  • Field-installing cable and panel-mount options
  • Moulded straight and right-angle variants
  • Pin range – 2, 3, 4, 5, 6, 8, 12 and 17 positions
  • Shielded options PVC or PUR

You can view our range by visiting our on-line catalogue.

If you don’t see what you need or you have bespoke requirements please get in touch, we have developed and manufactured new solutions for a wide range of applications and industries.

Mueller Electric Europe

Unit 9, Castle Park Industrial Estate, Queens Drive,
Nottingham NG2 1AH, United Kingdom
Tel: +44 (0) 1159 933300
Fax: +44 (0) 1159 933301

E-Mail: thearn@muellerelectric.com
Website: https://www.muellerelectric.com

This slideshow requires JavaScript.

You may also like...