What are the system limits of the OPC UA Server with S7-1500 and S7-1200?
1. System limits of OPC UA server for S7-1500 CPUs
Table 1 shows the system limits of the OPC UA Server with S7-1500 with firmware V2.8.x:
|1510, 1511, 1512, 1513||1515, 1516, 1505S||1517, 1518, 1507S|
|Maximum number of subscriptions with more than 1000 monitored elements per subscription over all sessions||10||10|
Maximum number of subscriptions with a maximum of 1000 monitored elements per subscription over all sessions
|Maximum number of subscriptions per session||20||20||20|
|Smallest possible sampling interval||100 ms||100 ms||10 ms|
|Smallest possible Send interval||500 ms||200 ms||10 ms|
|Maximum number of sessions||32||48||64|
- The number of 10,000 elements per subscription is always the maximum.
- A subscription with a maximum of 1000 elements cannot be converted into a subscription with more than 1000 elements.
- With regard to performance, it does not matter over how many subscriptions the elements to be monitored are distributed.
- Variant A: Large number of subscriptions with small number of elements.
- Variant B: Small number of subscriptions and large number of elements.
- The difference is the larger main memory requirement in Variant A.
- If you try to register more elements in a subscription than specified in the table above, the status code "BadTooManyMonitoredItems" is returned in the OPC UA client. In this case the client should attempt to register the remaining elements via another subscription.
- If the maximum quantity framework of the OPC UA server is exceeded, the OPC UA server sends the status "BadOutOfMemory" to the OPC UA client.
- Independent of the system limits mentioned above it is recommended not to exceed the number of elements to be monitored specified in Table 2 as overall quantity framework of the server.
1510, 1511, 1511C,
|1515, 1516||1517, 1518, 1507S|
|* Recommended maximum number of monitored elements over all subscriptions||1000||2000||10000|
* These recommendations are based on a user program with the following conditions:
- Only OPC UA communication (no other communication, like TCP, for example, is executed).
- Sampling and Send interval of 1 second.
- No OBs with priority greater than 15 (this means no interruption of the communication through OB processing).
50% maximum communication load
Data type of the elements: WSTRING
2. System limits of OPC UA server for S7-1200 CPUs
Adjacent table shows the system limits of the OPC UA Server with S7-1200 with firmware V4.5:
|Minimal sampling interval||100 ms, 250 ms, 500 ms, 1000 ms, 5000 ms, 10000 ms|
|Minimum publishing interval||200 ms||20.000.000 ms|
|Number of sessions||10|
|Number of subscriptions per session||50|
Number of nodes for user-defined server interfaces
|Max monitored nodes||100|
3. Further Information
More information you will find in the TIA Portal information system, under:
- Which restrictions do you have to consider with the OPC UA Server of S7-1500 CPU with the firmware V2.0.x or V2.1.x in compatibility mode of firmware V2.5?
- What are the possible causes and remedies for appearance of the status code in the OPC UA client when using subscriptions?
- Settings for the OPC UA server
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- You want to discuss in our forum and exchange experiences with other users
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