# Mitsubishi MC protocol (SLMP)

> Connect MELSEC iQ-R, iQ-F, Q and L controllers with the MC protocol over Ethernet and use their devices in OPC UA, SCADA and reports.

The MC protocol (MELSEC communication protocol, in newer documents SLMP) gives direct access to the device memory of Mitsubishi controllers. PLCGateway supports the QnA-compatible 3E frame and the 4E frame, each in binary and ASCII coding, over TCP or UDP.

Word devices are merged into blocks of up to 960 words and bit devices are read as 16-bit words, so even large device lists need only a few requests. For iQ-R the extended device codes are used automatically when the series is set.

- **Driver id:** `mc3e_binary`, `mc3e_ascii`, `mc4e_binary`, `mc4e_ascii`
- **Connection:** TCP / UDP · binary or ASCII
- **Address browsing:** addresses are typed or imported
- **Writing:** yes
- **Included in:** PLCGateway Connect, PLCGateway SCADA, PLCGateway Embedded

## What PLCGateway reads and writes

- Data registers D, link registers W, file registers R and ZR
- Bit devices M, L, F, V, B, X, Y, SM and special registers SD
- Hexadecimally numbered devices such as X1A or W1F0
- Timers and counters: current value, contact and coil
- Bits of word devices (D100.3) and 32-bit values across two registers
- Writing of words and bits

## Address examples

| Address | Meaning |
|---|---|
| `D100` | Data register 100 |
| `D200 (FLOAT32)` | REAL value in D200–D201 |
| `D100.3` | Bit 3 of D100 |
| `M100 · SM400` | Internal relay / special relay |
| `X1A · Y20 · W1F0` | Hexadecimally numbered devices |
| `ZR1000 · TN5 · CN3` | File register / timer value / counter value |

## Controllers and devices

- [Mitsubishi Electric MELSEC](https://plcgateway.com/controllers/mitsubishi.md)

## Connect in a few steps

1. In GX Works open an Ethernet port for the MC protocol (SLMP) as TCP or UDP and allow writing in RUN if values are to be written.
2. Add a device with frame (3E or 4E), coding (binary or ASCII), IP address and port, and choose the series (Q/L/FX5 or iQ-R).
3. Enter the device addresses as tags or import them from CSV and test the connection.
4. Share the values over OPC UA or use them in screens, reports and OEE.

## Questions and answers

### Is SLMP the same as the MC protocol?

SLMP is the name Mitsubishi uses for the MC protocol on newer controllers; the 3E and 4E frames are compatible. PLCGateway works with both names.

### Does it work with the FX5U built-in Ethernet port?

Yes. Configure an SLMP connection on the built-in port in GX Works3 and select the series Q/L/FX5 in PLCGateway.

### Are older FX3 controllers supported?

FX3 controllers with an Ethernet adapter use a different (1E) frame. Connect them through a gateway that offers Modbus TCP or OPC UA, or ask us about your installation.

## Related protocols

- [Omron FINS](https://plcgateway.com/protocols/omron-fins.md)
- [Siemens S7](https://plcgateway.com/protocols/siemens-s7.md)
- [Modbus TCP / RTU](https://plcgateway.com/protocols/modbus.md)
- [All protocols](https://plcgateway.com/protocols.md)

_Product and model names are trademarks of their owners. They are named only to show which equipment the drivers communicate with; PLCGateway is not affiliated with these companies._

---
Source: https://plcgateway.com/protocols/mitsubishi-mc