Useful updates for future improvement (#2)

* Included reading of transfer and elog channels at __init__ to update respective attributes with channels previously set at Oxygen

* Included elogContext method to use elog start and stop in a with statement

* Included missing ELOG timestamp for setElogTimestamp

* Included _localElogStartTime attribute to track locally when Elog started

* Included False return for fetchElog in case of error fetched

* Fixed getTransferChannels timing out when there are no channels available

* Removed unecessary logging when class is initialized by adding the "add_log" flag at _getTransferChannels and _getElogChannels.

* Fixed fetchElog method splitting array unaccordingly when timestamp is set to OFF. Included attribute that stores the elog timestamp.

* Included _convertElogArray method to convert matrix of strings from elog fetch into matrix of float (or datetime) values.

* Included fetchElogAccumulated

* Included elogTimestamp attribute at __init__

* Included error handling for elog example in case of timeout.

* Increased continuous fetching waiting time for elogFetchAccumulate to 50ms and fixed timeout docstring.

* Fixed fetchElogAccumulated not raising Exception for invalid timestamp configurations.

* Included type annotations for some Elog functions.

---------

Co-authored-by: Matthias Straka <[email protected]>

oxygenscpi_example.py

@@ -47,4 +47,41 @@
 mDevice.storeStop()
 print("Recording stopped.")
 
+# Set Elog channels and fetch some elog data
+mDevice.setElogChannels(["AI 4/I1","AI 4/I2"])
+mDevice.setElogTimestamp('ABS')
+mDevice.setElogPeriod(0.01)
+print("Starting Elog")
+mDevice.startElog()
+print("Waiting for 10 seconds...")
+time.sleep(10)
+print("Fetching elog Data")
+data1 = mDevice.fetchElog()
+data2 = mDevice.fetchElog()
+mDevice.stopElog()
+print("Elog stopped.")
+if data1:
+    print(f"First Elog row values fetched: {data1[0]}")
+else:
+    print("Unable to fetch Elog.")
+if data2:
+    print(f"Last Elog row values fetched: {data2[-1]}")
+else:
+    print("Unable to fetch Elog.")
+
+# Alternatively Start elog with context manager and accumulating values
+# for 10 seconds
+print("Starting Elog with context manager")
+mDevice.setElogTimestamp('ELOG')
+with mDevice.elogContext():
+    print("Waiting for 10 seconds...")
+    time.sleep(10)
+    print("Fetching Elog")
+    data = mDevice.fetchElogAccumulated()
+print("Elog stopped.")
+if data:
+    print(f"Fetched Elog from timestamp {data[0][0]} to {data[-1][0]}s.")
+else:
+    print("Unable to fetch Elog.")
+
 mDevice.disconnect()