User Manual
MAPware-7000 Programming Manual 239
1010-1040, Rev. 02
Chapter 8 - Data Logger and Trending
Data Logger
The Data Logger is used to record the values of tags (either memory built-in to the HMC or from
an attached PLC) over time. The collected data is stored in non-volatile memory inside the HMC7000. This
data can be displayed in graphic format on the HMC using the Historical Trend Object. You can
also upload the collected data to a computer (using MAPware-7000) or to an attached USB Flash drive
as a CSV file. The Data Logging feature is most often used for data acquisition. The HMC7000
gathers and saves valuable information about the industrial system it is connected to. This
information can then be reviewed at any time to increase knowledge of what is happening in
the system, perhaps to make it more efficient.
Factors to consider when creating a data log
Before you begin configuring the Data Logger function, you need to determine the following:
How much internal HMC memory will you need? During data logger setup, you have the
option of allocating 256KB, 512KB, 1024KB, or 2028KB reserved memory to be allocated
for the data you are collecting. To compute the amount of memory required, consider:
o Data Type used (i.e. 2 byte Integer or 4 byte Integer/Float)
o Number of Tags that you will be recording
o How often you will be recording (time interval)
o Total length of time that you wish to capture
For example, I want to capture data from five registers in my PLC. I want to read these
registers every 5 seconds over a period of one 24 hour period. The registers are 16 bit
data type.
Therefore, my calculations for memory requirements are:
2 (bytes per 16 bit register)* 5 (no of registers) = 10 bytes + 8 bytes overhead for
capturing the date and time of each data read. Total is 18 bytes.
I will be reading 12 times per minute which means 720 times per hour which means
17280 times per 24 hour period.
Therefore, I will need 18 (bytes per reading) * 17280 = 311040 bytes or 311KB.
Do you want the option to erase the Data Logger Memory during project download? If
Project Configuration dialog box. This dialog appears whenever you start a new project,