M12 A-coded pinout: 4-pin and 5-pin wiring reference

Four-pin and five-pin color reference

The Renhotec M-series catalog lists brown at pin 1, white at pin 2, blue at pin 3 and black at pin 4 for four-contact A-coded cables. Its five-contact A-coded reference adds gray at pin 5. The connected device determines each conductor’s function.

Identify the connector coding, contact count and viewing direction before using a diagram. A mating-face view shows the contacts you see when looking into the disconnected connector. A termination-side drawing shows the rear of the insert and must be read in its stated orientation.

Source: Renhotec M-Series Connector Catalog, printed page 38 (PDF page 41), “M12 wire definition.” These are the catalog’s conventional assignments; custom assemblies require their own wire map. This reference covers four- and five-contact A-coding only.

Keep the key aligned when comparing male and female faces

These mating-face views show the disconnected contacts with the key at the bottom. Pin 1 is lower left on the male and lower right on the female. The same numbered contacts meet when the connectors face each other.

4-contact A-coded

Male

Female

5-contact A-coded

Male

Female

Numbering: Renhotec M-series catalog, printed page 38, rotated from key-up to key-down here. The five-contact view also agrees with Phoenix Contact 1454545, page 6. Simplified geometry, not to scale.

A termination-side drawing looks at the rear of the insert. Read its stated orientation and terminal markings; do not copy the front-view positions onto screw terminals. A photograph can show a key and contact marks, but it cannot establish hidden wiring.

Separate cable colors from sensor functions

A cable drawing identifies conductor connections. A sensor diagram identifies supply and signals. The input module or IO-Link master diagram identifies what the receiving port expects. All three must agree.

For a concrete IO-Link example, ifm’s data splitter description distinguishes communication on pin 4 from the device-dependent signals passed on other pins. It illustrates why a general color chart cannot serve as the wiring instruction for every device.

PNP and NPN describe output behavior; they do not change the physical M12 housing into a different connector family. Match the sensor output to the controller input. For analog devices, confirm the signal type and return arrangement instead of assuming a digital-sensor diagram applies.

From a four-contact sensor port to a Renhotec cable

Single-ended cable example

RHT-M12006-04-C-XXX

Renhotec lists this as a straight, four-contact A-coded female cable, single-ended and shielded. It is a candidate when a sensor’s male A-coded port needs a cable to individual controller terminals.

The four sockets and key identify the connector end. Cable length, conductor termination and shield connection must match the installation.

Use the product page to identify the candidate cable, then request its current assembly drawing with your device diagram, required length and shield termination. For another contact count or cable end, browse the M12 A-coded cable range.

How to check an M12 sensor connection

1. Identify both device ports

   Record the sensor and input-module model numbers. Read the voltage, signal type, coding, contact count and pin assignment from their documentation. Isolate power before handling the connection.

2. Identify the cable ends

   Specify male/female, straight/angled, A-coding and contact count separately. A cable with a free wire end needs a conductor map; an extension cable needs an end-to-end map.

3. Match each circuit by number

   Build a short list from device pin to cable conductor to controller terminal. Use the actual cable colors. Include unused conductors and shield/drain connections so they are not accidentally assigned a function.

4. Check the disconnected assembly

   Inspect contact condition and use a suitable continuity method for the isolated cable when required. Keep test probes and procedures appropriate to the contacts. Do not test through powered electronics or assume a continuity result qualifies insulation and current capability.

5. Terminate and secure it to the product instructions

   Use the specified stripping dimensions, termination method, cable diameter and tightening instructions. Fit seals correctly and maintain the permitted bend radius. A generic M12 diagram does not supply these model-specific values.

6. Verify the signal at the receiving system

   Restore operation under the equipment procedure and confirm the expected sensor state or communication. Record the result at the controller, not only the sensor’s indicator lamp.

For an overmolded cable, do not reopen the molded connector to make a different assignment. Order the required wiring or an approved assembly. For a repairable field-wireable connector, check whether the terminal range and sealing parts match the chosen cable.

Can a five-pin cable replace a four-pin cable?

It may be suitable in a documented combination, but the extra contact alone does not establish compatibility. Check the mating interfaces, complete pin map, electrical ratings and the treatment of the extra conductor.

Check the ratings of the replacement itself. A four-contact product’s current or voltage rating does not automatically apply to a five-contact version.

Use the symptom to choose the next check