SD Ladder Functions

Use the SD ladder functions to read and write data to and from an SD card.

The functions are located on the SD menu on the Ladder toolbar.

If you include SD functions in your application, build a net that uses SB 217 to check that the SD card is in the PLC and correctly formatted, and SB 218 to check that the card is write-enabled, if it contains a write-protection tab

SD card Functions

Category	Purpose	Functions
SD Password	Use this to guard SD data.	Set SD Card Password
Folder Report	Reports the number of files currently in an SD folder, and the number of files can still be created in that folder.	Folder Report Function
SD Data Table	Use these to read and write data between Data Tables and SD card.	Log Data Table Row to SD Card Copy PLC Data Table to SD Copy SD to PLC Data Table Find Index or Tag in .udt
SD Trend	Record an entire or partial trend to a .utr file in the SD card Trends folder.	Save Trend to SD Card Stop Saving Trend to SD
SD Excel	Use Create Excel Line to pull numeric data or text strings from the PLC and use delimiters to structure a line; then use the function Write Delimited Line to create an Excel file on an SD Card. The functions can create .csv and .txt lines.	Create Excel Delimited Line Write Excel Delimited Line to SD
Data Blocks	Use these to create data storage areas in the SdBLocks folder on a SD card. SD Data Blocks may reach a total of 4G, or a single Block may be up to 4G. A Data Block comprises Sub-Blocks of 512 Bytes	Create SD Block Read from SD Block to Vector Write from Vector to SD Block
Data Files	Use Windows Explorer to store any type of file onto an SD card, such as .html or .jpg. The SD File Functions enable your Ladder application to read and write these files in 'chunks' of 512 bytes. You can also use these functions to pull data from the PLC and create files on the SD card.	SD File: Open Read/Write next Chunk SD File: Close Delete SD File SD File Info Rename SD File
Safely Remove SD	Use this to ascertain when an SD card may be safely removed from the PLC.	Remove SD
Clone to/from SD	Use this to clone a complete PLC and application, Data Tables, or operand values from a PLC or install such clone files to a PLC of the same model.	Clone to/from SD

PLC Name

If you apply a PLC name, the PLC writes this name to the files it creates on the SD Card.

HMI Progress Bar

You can use SI 330 and SI 331 to create a progress bar on an HMI display that shows when the PLC is writing data to the SD; and SI 332 and SI333 to show data being written from the SD to the PLC. To create a progress bar, use the elements shown in the following image. Note that the PLC copies data at a rate of .5k per second. This means that a PLC requires approximately 24 seconds to transfer a Data Table comprising 120k to an SD card.

Removing the SD Card

To indicate that the SD card may be safely removed, you can link an HMI element to SB 219 SD FIFO Empty (SD Card may be Ejected).