From ef8ea2fd5b3ffc28d179015b6f3615b4eeec4f84 Mon Sep 17 00:00:00 2001
From: Shreyan Das <72906700+sdspot2034@users.noreply.github.com>
Date: Thu, 19 Jan 2023 12:31:56 +0530
Subject: [PATCH] Create client-for-historian-nodes.py

Example of a client reading history data from an OPC Server with historized nodes
---
 examples/client-for-historian-nodes.py | 40 ++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 examples/client-for-historian-nodes.py

diff --git a/examples/client-for-historian-nodes.py b/examples/client-for-historian-nodes.py
new file mode 100644
index 00000000..804fe0ce
--- /dev/null
+++ b/examples/client-for-historian-nodes.py
@@ -0,0 +1,40 @@
+import datetime
+import sys
+from opcua import Client, ua
+
+
+# Connect to the OPC server
+url = "opc.tcp://localhost:4840"
+client = Client(url)
+client.connect()
+
+# Define the tags to fetch
+tags = ["ns=2;i=2"]
+
+# Define the start and end time for the historical data
+end_time = datetime.datetime.utcnow()
+start_time = end_time - datetime.timedelta(hours=1)
+
+
+try:
+    # Fetch the historian data
+    historian_data = []
+    for tag in tags:
+        node = client.get_node(tag)
+        data = node.read_raw_history(start_time, end_time, numvalues=0)
+        historian_data.append((tag, data))
+
+    # Print the data
+    for tag, values in historian_data:
+        print(tag)
+        for value in values:
+            print(value)
+
+
+except Exception as e:
+    print(e)
+    sys.exit()
+
+finally:
+    # Disconnect from the OPC server
+    client.disconnect()