Troubleshooting – Data Logging

Data Logging Errors

Below are some helpful troubleshooting steps to resolve common data logging errors.



Use Configure-License to verify that the Data Historian product feature is enabled.

Menu Configure License

Licensed Features

System Errors

Select Configure-System Errors and expand any Data Log errors to see the details of the error.

Menu Configure System Errors

Data Log System Errors

The information provided can often help you determine the cause of data logging failure.

The history of all systems errors can be found in the OAS Error Log specified under Configure-Options-System Logging.

Menu Configure Options

Error Log Path

Log Data Logging Transactions

You can enable Log Data Logging Transactions under Configure-Options-System Logging to track and record all transactions for each logging group.

Menu Configure Options

Log Data Logging Transactions

Specify the location of where the transaction logs will be saved with the property Transaction Log Path further down in System Logging.

Transaction Log Path

All transactions will be recorded in the individual file for each logging group with the name of the file containing the logging group name.

The log will contain both any database errors and the values to be logged.


09:29:25.072 Tags and Values to be processed:
Tag: Ramp.Value
TimeStamp: 10/18/2022 09:29:25.000
Quality: True
Value: 65


If the Server under the database tab is unreachable or incorrectly defined a System Error will indicate the database cannot be opened or created.

Menu Configure Data Logging

Data Log Server

Use the database admin tool like SQL Server Management Studio, pgAdmin4, or other appropriate database tool to see if it can connect to the local or remote database engine from the system OAS is running on.

If Set Server Name with Tag is enabled verify that the value of the string tag defined is the correct server name.  Try a static server name if so by disabling Set Server Name with Tag.

Security Access

Set the correct User Name and Password credentials from the database engine with access to create databases, tables, and field names along with the rights to insert and update records.

Menu Configure Data Logging

DB Windows Authentication

DB User Authentication

If logging to SQL Server see Database Security Login to define login access in the database engine.

Logging Active

The logging group needs to be active in order to process values to the database or CSV file.

Verify that Logging Active is enabled under the Common tab of the logging group.

Menu Configure Data Logging

Logging Active

If Active Logging with Tag is enabled verify that the Boolean tag defined is true and good quality.  Also verify that the tag and variable name is properly defined.

Event and Snapshot Trigger Tag

If the Logging Type is set to Event Driven, Event Driven Narrow, or Snapshot recording verify that the Trigger Tag is properly defined using the Browse button to an Integer or Boolean tag variable. 

Menu Configure Data Logging

Trigger Tag

Also verify that the value of the Trigger Tag is changing state using Configure-Tags.

Store and Forward

When there is an unresolved error data will be buffered to the Store and Forward directory specified under Configure-Options-Store and Forward. 

Menu Configure Options

Store and Forward

Check the directory specified for the store and forward location to see if any .dlb files are being buffered for the logging group.  If there are files being go to Configure-System Errors to see what Data Log error is causing the data buffering.

Data from the buffered files will be the first to be processed and must be resolved to move onto the next set of data, so current data will not be able to be logged until the store and forward buffered files can be processed.

You can extract the contents of any buffer file with the Data Buffer to CSV program under the Open Automation Software program group.

To discard the data within the buffer files and move onto the next record there are 3 options.

  1. Delete the oldest buffer file with the file name containing the data logging group name.
  2. If the System Error shows Null value being rejected see Null Value cause and resolution in the next cause.
  3. Enable the property Do Not Buffer Data On Error under the Common tab of the logging group.  Note: Enabling this property will disable the Store and Forward feature for the logging group.

Menu Configure Data Logging

Do Not Buffer Data On Error

Null Value

A null value will be recorded to the database or CSV file under one of the following conditions.

  1. The data quality of the tag to be logged is bad quality.  Use Configure-Tags to check the tag is good quality and contains a value that can be logged to the database field data type.
  2. The tag name is not correctly defined or does not exist. Check the Tag Parameter under the Tags tab of the logging group of each field if it exists and ends with one of the over 700+ Tag Variables such as .Value, .HighHighAlarmLimit, or .HighHighAlarmActive.

Note: Tag names are case sensitive.

Null Value Not Allowed

If one or more of the table columns has been modified to not allow null values in the field data will be buffered to the Store and Forward directory if the data quality of a tag to be logged is bad.

There are 2 solutions to resolve this conflict.

1. Change the field definition back to Allow Nulls.  First check with the database admin to why it was change to not allow null values in case there is a downstream report depending on the data.

Allow Null Values

2. Enable the property Discard Null Rejects under the Database tab of the logging group.

Menu Configure Data Logging

Discard Null Rejects

Create Table and Fields

If the table or field added is not automatically created in the database verify that Create Table and Fields is enabled under the Database tab of the logging group.

Menu Configure Data Logging

Create Table and Fields

Existing Table

If setting up logging to a table that already exists verify that the either all of the fields are correctly defined with the right data type or the fields that are not being logged to allow null values.

Database Triggers

If one or more database triggers is defined to a table note that the logging rate and reliability will be impacted by the trigger's ability to complete.

If data is not being logged or slow to arrive in the database with no System Error reported check the table in the database engine if there are Triggers defined.  If there are Triggers check with the database admin if the triggers can be removed or revised to complete quickly and reliably.

DB Triggers

Note: If you need the Triggers to fire disable the bulk insert logging by setting the property Records to Enable Bulk Insert to 10000000.

Menu Configure Data Logging

Records to Enable Bulk Insert


The DateAndTime field will record the timestamp from the data source. If tags being logged from an OPC server and the time delivered is different than the local CPU time this can be overridden to use the local CPU clock at the data source of the Tag by setting the property Use TimeStamp from OPC Servers under Configure-Options-OPC to false.

Timestamp OPC Servers

To view the timestamp of any tag go to Configure-Tags and select the tag or parent group and select Add to Watch.  View the Watch Window article for an example of use.

Different Time Zones

It is not possible to log remote tag values from a different time zone using Continuous or Continuous Narrow with the local time.  In this configuration data must be logged with UTC time.  To enable UTC time enable the property Convert Timestamps to UTC under the Common tab.

Menu Configure Data Logging

Convert Timestamps to UTC

Another option is to set all tag values to UTC at the data source engine with the option Use UTC Timestamp under Configure-Options-Time.

Menu Configure Options

Use UTC Time

DateAndTime Field Resolution

By default the DateAndTime field defined under the Tags tab is set to High Resolution with 100 nanosecond resolution.  When logging to older versions of SQL Server, Oralce, or mySQL and the System Error Cannot find data type DateTime2 is reported uncheck the property High Precision under the Tags tab of the logging group.

Menu Configure Data Logging

Date Time High Precision

CSV File with Excel

When logging to a CSV file store and forward will be enabled when Excel opens the CSV file currently logged to.  Excel locks files for exclusive use when it has a file open.  There will be no data loss during this time and all data will be logged when Excel closes the file.

MS Access Error microsoft.ace.oledb.12.0 provider is not registered
MS Access Class not Registered System Error

For Office 2010, the following update will correct this issue.

For Office 365 (please note, by default Office365 installs the 32-bit version regardless of your system), use:

Data Logging System Error occurs with database engine error null values not allow.
The cause of this error is one or more of the database table columns has been modified  to not allow null values.  OAS creates the columns in the table to allow null values so when the data quality is bad for a tag value a null value will be inserted into the table.  The only column that should be set to not allow null values is the DateAndTime column.  There are 2 solutions to this error:
  1. Please review the columns in each table with the SQL Server Management Studio.  If they have been changed to not allow null values change them back to allow null values.
  2. Go to each logging group and enable the property Discard Null Rejects under the Database tab.  Keep in mind that with this property enabled the records to be logged that contain null values will be discarded and not logged.
Menu Configure Data Logging Discard Null Rejects
CSV Logging to a Remote Mapped Drive
Either enable the SYSTEM account to have read and write access to the mapped drive and directory, or set the OAS Engine Service LogOn to a user account that would have access to the remote mapped drive using these steps in setting the OAS Engine Service LogOn.
Logging to MS Access on a Remote Mapped Drive
Either enable the SYSTEM account to have read and write access to the mapped drive and directory, or set the OAS Reports Service LogOn to a user account that would have read and write access to the remote mapped drive.
Database Security Login
When you receive an error for Data Logging, Alarm Logging, or Recipe that there is a problem with the login security to the database engine in trying to open it or create it follow these steps which are shown for SQL Server, and would be similar to the other database engines.

Step 1

Start SQL Server Management Studio and connect to the database engine. Database Security Login 1

Step 2

Select the database engine in the Object Explorer and right click to select Properties.
Select Permissions on the left and choose NT AUTHORITY\SYSTEM or the user you are using with SQL login and Grant all permissions.
Note: NT AUTHORITY\SYSTEM is the account that the OAS Engine runs under by default and would be used when the Data Logging Group, Alarm Logging Group, or Recipe Group is using Windows Authentication for login.  If it is a remote database engine choose the Name of the system where OAS is running. Select OK

Step 3

Select Security-Logins in the database engine tree.
Database Security Login 2
For Windows Authentication Login open the PC account that the OAS Database Service is running on this would be NT AUTHORITY\SYSTEM for the local system. For SQL Server Login either add a new account or select an existing account where you know the password. For SQL Server login make sure the property to Enforce password expiration is disabled: Database Security Login 3
Under Server Roles enable all properties or at least sysadmin and public.
Database Security Login 4
Select OK and return to OAS to see if the Login error has been resolved.
If you still encounter a security access error select User Mapping and select the database you want to access to enable all properties except db_denydatareader and db_denydatawriter. Database Security Login 5
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