IEC 60870-5-104 (Power Telecontrol)
IEC 60870-5-104 — the telecontrol standard for transmission, distribution, and generation systems (TCP 2404). Because RTUs and gateways push measurements and statuses upstream, the gateway holds the values and then exposes them to tags.
| Situation | Which card to use |
|---|---|
| RTU · Grid Gateway · Remote Monitoring | IEC-104 (this page) |
| Substation IED · Protection Relays | IEC 61850 |
| North American utility SCADA | DNP3 |
| General Instruments · Inverters | Modbus TCP |
Registration Form Input Values
| Input Field | What to Enter | Example |
|---|---|---|
| IP Address | RTU · Gateway address | 10.20.30.40 |
| Port | Standard 2404 | 2404 |
| Collection Period | Interval for reading from the cache (ms) | 1000 |
Options
| Option | Default | Description |
|---|---|---|
common-address | 1 | ASDU common address. Must match the value configured on the equipment |
general-interrogation | On | Requests all values once immediately after connection |
common-address is different, "the connection works but no values appear"If TCP connects and STARTDT is exchanged but tags remain empty, this is almost certainly the issue. Check the ASDU address in the equipment's configuration screen and align it.
Tag PLC Address Notation — IOA
Tag's PLC Address = IOA (Information Object Address, integer).
| Format | Meaning |
|---|---|
1001 | IOA 1001 |
13:1001 | Ignores the preceding type identifier and reads as IOA 1001 |
We accept the 13:1001 format so that you can paste tag lists from other SCADA systems directly — since the type is determined from the value itself, this is at least harmless.
Not Polling — "Hold & Provide"
접속 ─▶ STARTDT ─▶ 일반심문(전체 값 요청)
│
RTU 가 값이 바뀔 때마다 밀어 준다
▼
게이트웨이가 IOA 별로 최신값을 담아 둔다
│
수집 주기마다 태그가 그 캐시를 읽는다
🔴 Shortening the collection period does not increase RTU load. The period is merely the interval at which the cache is read; the rate at which values arrive is determined by the RTU. Conversely, if the RTU doesn't send, no matter how short you set the period, values won't refresh.
When Things Don't Work
| Symptom | What to Check First |
|---|---|
| Connection fails entirely | 2404 firewall, whether the RTU allows this gateway's IP |
| Connection works but all values are empty | common-address, and whether general-interrogation is enabled |
| Only some IOAs are empty | Whether the RTU actually sends that IOA (band configuration) |
| Values stop updating | The RTU session may have died — try disconnecting and reconnecting |