The following restrictions apply with the delivery of the SIMATIC S7 Connector application.
Configuration update
Whenever you change the configuration in the SIMATIC S7 Connector application, the system app on the respective Industrial Edge Device (IED) gets updated only when you click on the Deploy button.
You can check the status of the configuration update using the tasks icon in the IED UI.
Multiple user access to system configurators
For the system configurators, it is not possible to use the same system configurator of an IED with two or more users' instances at the same time. When another user launches a system configurator while a current user is already working with it, the second user is blocked, and the primary user continues working with the system configurator. Just when the primary user closes the system configurator, the second user can launch the same system configurator.
Supported language
When you provide the needed information in input fields, the Industrial Edge Management (IEM), the system configurators, and other components only support characters from the English language. For example, when you add a data source and tag name with special characters like ö, ä, or ü, these characters are not supported and result in error messages.
Updating system configurators
- When you update the system configurators in the IEM, there is no specific defined sequence for updating the configurators.
- When you update the system configurators, you must ensure to select the 'nginx conf' file during the process. The selected file is displayed with green-check circle.
Before you update the system configurators, take a snapshot of the cluster respectively the VM.
Job management for system configurators
The job management for all system configurators is not handled by the system configurators themselves but by the IEM. In case of any job failure, you are notified by the configurators. In that case, check the jobs in the IED UI respectively in the IEM and delete the failed or skipped jobs from the Job Status screen.
CPU Spike Issue
Under resource constraints, the tags may be repeated with different timestamps within the same packet. This behavior can happen temporarily under sudden spike in resource usage of other processes limiting the resources availability for SIMATIC S7 Connector. To reproduce this scenario, follow these steps:
- Configure an IED VM with 1CPU core count and 2GB RAM.
- Install SIMATIC S7 Connector, Databus, Flow Creator, and IE Cloud Connector applications.
- Configure data points in SIMATIC S7 Connector with low acquisition cycle supported by the connection.
If tags are repeated and you are interested only in the newest data available in the packet, then follow these steps:
- Parse the tag data packet received from the broker.
- Create a map with id as the key to hold the unique tag values.
- In case id is repeated, replace the tag data which has maximum ts value in the packet.
If tags are repeated and you are interested in all the packets with no data loss, then follow these steps:
- Parse the tag data packet received from the broker.
- Create a multi-map with id as the key to hold the multiple tag values for the same tag.
- Sort the tags with increasing order of timestamp before processing/storage.
Data Publishing Interval
TIME, LTIME, TOD, and LTOD values are published as nanosecond in 100 nanoseconds intervals.
Reverify Metadata Payload based on Checksum Hash
In the metadata payload, hash of the data configured are published to the broker after each deploy. This hash is calculated based on CRC32 hashing algorithm with Castagnoli as the constant polynomial. Hash is calculated for the connections value object in the metadata payload. In case the IED or S7 Connector application restarts, the metadata with the same hash value is published again when S7 Connector application reconnects to the broker.
Configure Job Scheduling Interval from IEM to IED
By default the time to schedule a job from IEM to IED is set as 1 minute in the IED. To ensure faster scheduling of job, set the Edge Management Notifications to 10 seconds under the “Settings” bar of IED as shown below:
Info
User must ensure IEM and IED time is in sync.
Handling Tags based on Quality Code
- When PLC connection is interrupted and if runtime is running, the app publishes the last published Tag value with Quality Code as 0 (BAD). You must ensure to discard the value if Quality Code is 0. Once the PLC connection is established again, value is published with Quality Code as 3 (GOOD).
- When user has configured S7-300/400 PLC with Alarms enabled in the S7 Connector App, and if PLC goes into STOP Mode; the app publishes the last published Tag value with Quality Code as 0 (BAD) along with the Full Text Alarm. User has to ensure to discard the value if Quality code is 0. Once the PLC is in RUN Mode, value is published with Quality Code as 3 (GOOD) along with Full Text Alarm.
Memory Requirement
Total memory limit of SIMATIC S7 Connector Runtime is 540 MB.
Ports on Use
S7 and Optimized S7 protocol uses TCP port 102.