Data logger
The data logger enables the recording of measured values. The recording can be used for the analysis of errors. See also Chapter Troubleshooting with the data logger.
Once the recording has been started, it saves all measured values continuously in a ring buffer. The recording stops automatically if a protective function signals an error. With the recorded measured values you can trace the events that led to the error.
Activate control
You have to activate additional process data objects in the process image in order to be able to use the data logger:
- PDO 0x1610 (Sync Manager SM2 "Outputs")
- PDO 0x1A10 (Sync Manager SM3 "Inputs")
Proceed as follows:
- Requirement: an EP9224-0037 is appended in the I/O tree in TwinCAT.
- 1. Double-click on the EP9224-0037 I/O module in the I/O tree.
- 2. Click the Process Data tab.
- 3. Click "Outputs" in the "Sync Manager" box.
- 4. Activate the PDO Assignment (0x1C12) checkbox next to the entry "0x1610".
- The process data object "LOG Control" appears in the I/O tree.
- 5. Click "Inputs" in the Sync Manager box.
- 6. Activate the PDO Assignment (0x1C13) checkbox next to the entry "0x1A10".
- The process data object "LOG Status" appears in the I/O tree.
- Result: The process data objects for controlling the data logger are activated.
Parameterization
The sampling rate for the recording can be selected in the index 8040:11 "Sampling Rate".
Start recording
The output variable "Start Logger" is located in the process data object "LOG Control". The recording is started by a positive edge on this output variable.
If the recording is running, the Status bit
"LOG Status" > "Status" > "Logger Running"
is set.
Stop recording
The recording stops in two cases:
- if a protective function signals an error.
- upon a positive edge on the output variable
"LOG Control" > "Control" > "Stop Logger".
If the recording has stopped, the input variable
"LOG Status" > "Status" > "Logger Running"
has the value "0".
Evaluate recorded measured values
The recorded measured values are available as a .csv file. The file must be uploaded from the box to the control computer in order to be able to evaluate it.
Proceed as follows to upload the recorded measured values to the control computer:
- 1. Double-click on the EP9224-0037 I/O module in the I/O tree.
- 2. Click the "Online" tab.
- 3. Click the Upload button.
- A dialog box with the title "Save As" appears.
- 4. Select a directory and write in the field File Name:
"logdata.csv" - 5. Click the Save button.
- A dialog box appears with the title "Edit FoE Name".
- 6. Click the OK button.
- The file with the measured values was uploaded to the control computer.
File format
The file with the measured values begins with a header „**** Logfile from Ethercat Slave ****".
Below this follows:
- a file header
- a measured value table
Format of the file header:
Field | Description |
|---|---|
Device Name | Name of the module |
File Version | Version number |
Reason for which the snapshot was taken | Reason for stopping the data logger |
Age of snapshot | time elapsed from stopping the data logger until the upload |
System timestamp (0 if DC not supported) | current timestamp when uploading |
Format of the measured value table:
Type | Description |
|---|---|
Time offset additional to snapshot age | The age of the measured values in the row in relation to the stopping of the data logger (0 = stop, > 0 older values) in ms |
I(U...) | present current values of the channels Us / Up 1 - 4 in 100 mA |
Internal Temperature | internal module temperature in °C |
Us / Up | Input voltage Us and Up at the 7/8" input in V |
Sum Current Us / Up | Sum current of Us and Up in A |
I²t(U...) | virtual overload, incremented or decremented depending on the nominal current
|