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From this moment, the server informs the client about the changes in the monitored objects by
| Kotva |
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| publish_message |
|---|
| publish_message |
|---|
|
"Publish message" in the periodic intervals (that have been set in the parameters of
subscription). If the monitored objects have not been changed, the server will send a
"Publish message" once in (
Max KeepAlive Count *
Publishing Interval) seconds. The message informs the client that the
subscription is still active. A similar check mechanism is also on the client-side - it will send a
"Publish message" once every (
Max KeepAlive Count *
Publishing Interval). If the client does not send the acknowledgment
"Publish message" within (
LifeTime Count *
Publishing Interval), the
subscription will expire on the side of the server.
OPC UA communication was tested with:
- Simatic S-7 OPC UA Server
- Bernecker PLC embedded OPC UA Server
- Zenon OPC UA Server
| Kotva |
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| komunikacna_linka |
|---|
| komunikacna_linka |
|---|
|
Communication line configuration
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