Yaskawa MP900 Series MPLOGGER - Manual (Page 85)

5.5 Data Logging
5-9
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5.5 Data Logging
In this section, supplementary information is provided for the MPLOGGER Data Logging
Function.
Data logging is managed in tag groups. Multiple tags are assigned to one tag group and data is
collected and stored in a file on a cycle specified by each group.
1. Information specified in 4.9 Data Logging Settings are stored in MDB files that are
generated in a folder named “Data.” The MDB files use the following naming conven-
tion.
• Name of special workbook + “Log” + “.MDB”
For example, if a new workbook is created and named “MpLogl”, the MDB file
“MpLog1Log.MDB” will be created.
When the Data Communications Server receives a command to begin communications,
it retrieves the tags and tag groups, needed to collect data from this file.
2. Collected data is also stored in an MDB file.
The logging data is stored in an MDB file that is generated in the folder specified in 4.10
Saving the Log Data . The MDB files use the following naming convention.
• “ML” + YYYYMMDD + “_” + Name of special workbook + “.MDB”
For example, if a new workbook is created and named “MpLogl,” log data for Novem-
ber 20, 1998 will be stored in an MDB file named “ML19981120_MpLog1.MDB.”
Log data collected by the data collection server is temporarily queued in the memory of
the Data Communications Server to preserve the overall performance. When the queue
exceeds 100, or if one minute passes after queuing begins, the data is output to an MDB
file.
Because of this, care must be taken when using the log data as real-time trend data.
MPLOGGER does not have the ability to search or display the logged MDB files. Sepa-
rate functions, such as the database function in Excel or Access functions, must be used.
For information on the arrangement of log files, refer to Chapter 7 Log Database Con-
figuration .
When designing an application to access the log data, the MDB file cannot be accessed simultaneously
by two or more applications. Minimize the time required to access the database.
If a log data display program keeps the log database open for a long time, the Data Communications
Server cannot output log data and data may be lost. IMPORTANT