Category Archives: WinCC OA

WinCC OA OPC UA Server

For testing sometimes it is too hard to deal with security :-). To make the OPC UA server in WinCC OA unsecure add the following lines to the config file.

[opcuasrv]
disableSecurity = 1
enableAnonymous = 1

Add the WCCOAopcuasrv manager to the project and start it.

To publish datapoints don’t forget to add the datapoints to the DP groups “OPCUARead” and “OPCUAWrite”.

Python and WinCC OA…

Connected Python to WinCC OA through a Websocket Manager. Python programs can connect to WinCC OA and read/write datapoints. Communication is JSON based, it’s simple to use in Python, see examples below (ws://rocworks.no-ip.org can be used for tests, but will not be available all the time).

https://github.com/vogler75/oa4j-wss

  1. dpGet
  2. dpSet
  3. dpConnect
  4. dpQueryConnect
  5. dpGetPeriod
  6. … more functions will be implemented

Required Python modules:

  • pip3 install websocket-client
  • pip3 install matplotlib

############################################################
# Open Connection
############################################################
import json
import ssl
from websocket import create_connection
url='ws://rocworks.no-ip.org/winccoa?username=demo&password=demo'
ws = create_connection(url, sslopt={"cert_reqs": ssl.CERT_NONE})

############################################################
# dpGetPeriod
############################################################
cmd={'DpGetPeriod': {
 'Dps':['ExampleDP_Trend1.'],
 'T1': '2018-02-07T18:10:00.000', 
 'T2': '2018-02-07T23:59:59.999',
 'Count': 0, # Optional (Default=0)
 'Ts': 0 # Optional (0...no ts in result, 1...ts as ms since epoch, 2...ts as ISO8601)
 }}
ws.send(json.dumps(cmd))
res=json.loads(ws.recv())
#print(res)
if "System1:ExampleDP_Trend1.:_offline.._value" in res["DpGetPeriodResult"]["Values"]:
 values=res["DpGetPeriodResult"]["Values"]["System1:ExampleDP_Trend1.:_offline.._value"]
 print(values)
else:
 print("no data found")

# Plot result of dpGetPeriod
%matplotlib inline 
import matplotlib.pyplot as plt
plt.plot(values)
plt.ylabel('ExampleDP_Trend1.')
plt.show()

############################################################
# dpGet
############################################################
cmd={'DpGet': {'Dps':['ExampleDP_Trend1.', 'ExampleDP_Trend2.']}}
ws.send(json.dumps(cmd))
res=json.loads(ws.recv())
print(json.dumps(res, indent=4, sort_keys=True))

############################################################
# dpSet
############################################################
from random import randint
cmd={'DpSet': {'Wait': True, 
 'Values':[{'Dp':'ExampleDP_Trend1.','Value': randint(0, 9)}, 
 {'Dp':'ExampleDP_Trend2.','Value': randint(0, 9)}]}}
ws.send(json.dumps(cmd))
res=json.loads(ws.recv())
print(json.dumps(res, indent=4, sort_keys=True))

############################################################
# dpConnect
############################################################
from threading import Thread

def read():
    while True:
        res=json.loads(ws.recv())
        print(res)
Thread(target=read).start()
    
cmd={"DpConnect": {"Id": 1, "Dps": ["ExampleDP_Trend1."]}}
ws.send(json.dumps(cmd))



Streaming SQL for Apache Kafka & WinCC OA with Docker…

KSQL makes it easy to read, write, and process streaming data in real-time, at scale, using SQL-like semantics. It offers an easy way to express stream processing transformations as an alternative to writing an application in a programming language such as Java or Python. https://www.confluent.io/product/ksql/

With WinCC OA Java (https://github.com/vogler75/oa4j) we can stream data from WinCC OA to Apache Kafka, use KSQL to produce some insights and send it back to WinCC OA by using a WinCC OA Driver written in Java connected to Kafka.

Attached you will find a docker-compose.yml to setup KSQL + WinCC OA Connector and Driver to test it. Just use “docker-compose up -d” to start up everything. Before you should set the “data” and “event” environment variables in the docker-compose.yml to point to a running WinCC OA project.

root@docker1:~/docker/builds/winccoa# docker-compose up -d

Creating winccoa_frontend_1 ==> collect data from OA and publish it by ZeroMQ

Creating winccoa_backend-kafka_1 ==> get the data from the Frontend and write it to Kafka

Creating winccoa_driver-kafka_1 ==> OA driver to read data from kafka.

Creating winccoa_zookeeper_1
Creating winccoa_kafka_1
Creating winccoa_schema-registry_1
Creating winccoa_ksql-cli_1

We use Docker to startup WinCCOA Mangers (frontend, backend) and Drivers.

Afterwards you can start KSQL: docker-compose exec ksql-cli ksql-cli local –bootstrap-server kafka:29092

Create a stream of the topic which is sent from WinCC OA to kafka (currently every change of value in WinCC OA is sent to Kafka):

CREATE STREAM Scada_FloatVar (TimeMS BIGINT, Status BIGINT, Value DOUBLE) WITH (kafka_topic=’Scada_FloatVar’, value_format=’JSON’);

Create a result table in KSQL which will be read by the WinCC OA Driver, here we detect if a datapoint changes more often than 5 times in 10 seconds. Just a simple example to show how KSQL can be used:

CREATE TABLE result WITH (PARTITIONS=1) AS SELECT rowkey AS “Name”, count(*) AS “Value” FROM Scada_FloatVar WINDOW TUMBLING (size 10 second) GROUP BY rowkey HAVING count(*) > 5;

In WinCC OA you should put a peripheral address on a datapoint with the example driver (num 4) to get the result back (you will need the panels and scripts from here https://github.com/vogler75/oa4j/tree/master/Project/Drivers/Kafka to use the driver).

docker-compose.yml

SCADA System is tweeting….

This can be easily achieved by connecting WinCC OA to NodeRed by MQTT. From Node Red it is possible to connect to Twitter and publish tweets. I installed a MQTT server Mosquitto on my SCADA server and connected WinCC OA to this MQTT broker, so that I can send a datapoint value from WinCC OA to MQTT. Node-Red can read this tag from MQTT and publish the message to Twitter…

WinCC OA TwitterNodeRed Twitter

Monitoring with Logstash and WinCC OA…

Monitoring-Concept

 

For example we do this with the Oracle Alert Log. Very often an Oracle Database is used with WinCC OA to store history values. But a lot of times no one takes care of the Oracle database. At least the Alert-Log file should be observed. With Logstash, Apache Kafka and the WinCC OA Apache Kafka Driver we can send alert log messages from the Oracle database(s) to a WinCC OA monitoring system.

Oracle-Alert-Log

Observing WinCC OA Logs with Elasticsearch and Logstash…

With Logstash we can collect the logs of WinCC OA systems and write it to Elasticsearch. Multiple WinCC OA system’s can be observed with a central log database…

With Kibana the logs can be easily discovered – I now see errors what i haven’t seen before in my system…

In parallel the log messages are written to Apache Kafka. With Apache Spark we can now observe the log streams and detect anomalies… a very simple observation could be to just simple count the amount of log messages per timeframe …

logstash

WinCC OA logstash configuration file: winccoa-logstash-conf