# IEC 60870-5-104

> Connect RTUs, protection relays and substation gateways with IEC 104 and combine energy data with production and building data.

IEC 60870-5-104 is the standard telecontrol protocol of power utilities and many industrial substations. PLCGateway acts as the controlling station: after connecting it starts the data transfer, runs a general interrogation and keeps the spontaneous and cyclic messages of the station with their time tags.

Single and double points, measured values, integrated totals and step positions become tags with their quality; commands and set points are sent with direct execute and wait for the activation confirmation. This brings switchgear status and energy counters into the same SCADA, history and reports as the production machines.

- **Driver id:** `iec104`
- **Connection:** TCP 2404
- **Address browsing:** addresses are typed or imported
- **Writing:** yes
- **Included in:** PLCGateway Connect, PLCGateway SCADA, PLCGateway Embedded

## What PLCGateway reads and writes

- Single and double point information
- Measured values: normalized, scaled and short floating point
- Integrated totals (energy counters)
- Step positions and 32-bit bit strings
- Quality descriptors and CP56Time2a time tags
- Single and double commands, set points

## Address examples

| Address | Meaning |
|---|---|
| `sp:1001` | Single point, information object address 1001 |
| `dp:1002` | Double point (off, on, intermediate) |
| `me:2001` | Measured value |
| `it:3001` | Integrated total (counter) |
| `sc:5001 · dc:5002` | Single / double command |
| `2001.q · 2001.t` | Quality descriptor / time tag |

## Controllers and devices

- [Protection relays, IEDs and RTUs](https://plcgateway.com/controllers/protection-relays.md)

## Connect in a few steps

1. Agree on the common address and information object addresses with the station owner.
2. Add an IEC 104 device with IP address, port 2404 and common address.
3. Create the points as tags or import the point list from CSV.
4. Use energy and switchgear data in screens, alarms, energy management and reports.

## Questions and answers

### Can PLCGateway send commands?

Yes. Single and double commands and set points are sent with direct execute; the activation confirmation of the station is checked and a negative confirmation is reported.

### How is data quality handled?

Invalid values become bad, not topical values uncertain, and points the station never reported stay bad with the reason.

### Is IEC 101 (serial) supported?

No, PLCGateway supports the TCP/IP profile IEC 60870-5-104.

## Related protocols

- [DNP3 (IEEE 1815)](https://plcgateway.com/protocols/dnp3.md)
- [IEC 61850 MMS](https://plcgateway.com/protocols/iec-61850.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._

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Source: https://plcgateway.com/protocols/iec-60870-5-104