Overview
A live OPC UA server you can connect to right now: tags change on their own, history is available via HistoryRead, alarms arrive as Alarms & Conditions events. Nothing to install — connect your client: UaExpert, SCADA, HMI or ModbusToolkit.
Shared demo server
Always on, read-only. No key needed.
opc.tcp://opcua-sendbox.electroman.by:4840/electroman/
Tags ns=2;s=Tags.*
| Tag | Value | 60 s trend |
|---|---|---|
| Connecting… | ||
Alarms ns=2;s=Alarms.*
| Alarm | State |
|---|
Subscribe to events of the Server node or the SendBox folder. SineHigh fires when Sine is above 80, Heartbeat toggles every 10 s.
Personal server
Your own OPC UA server in a second
A separate server on its own port: add tags with generators, write values from your client, trigger alarms by hand.
Modbus TCP sandbox
Need Modbus TCP? Public server modbus-sendbox.electroman.by:5020: 10 slaves, values change on their own, faults on demand.
Open Modbus SendBoxServer counters
| Active connections | … |
| Requests/s | … |
| Errors/s | … |
| Total requests | … |
| Total errors | … |
| Uptime | … |
Requests are counted by the HTTP API; a response with status 400 and above counts as an error. Active connections are OPC UA clients of the shared server and personal sessions.
SendBox is free and ad-free. The server and the test bench are paid for by donations.