How To Automatically Unload Data From a DT8X Datalogger Using FTP

Using dataTaker’s Flexible DT8X Series Data Loggers

CHESTERLAND OH—September 20, 2011

This brief tutorial will show users how to automatically unload data from dataloggers in the popular DT8X series by using FTP. This is done to allow the loggers to periodically push the data automatically to a server without any user interaction required. Automatic unload is accomplished in a 2-step process involving creating a trigger to execute the unload command and by entering the unload command itself.

To begin, users need to create a timed schedule to execute the command needed to unload the data. The simplest way to trigger the command is to set a schedule to execute once a day. This can be done by setting the rate for the unload schedule to 1D. In this case, the schedule will be executed every day at midnight. However, if you have multiple data loggers, this may cause an issue if they all hit the FTP server at about the same time, so it may be desirable to stagger their unload times. In this case, it’s possible to use the internal variables for the day (4ST), hour (3ST), and minute (2ST) that are maintained by the internal real-time clock of the data logger. Using these variables it’s possible to create a schedule that will trigger an action to run at a specific time. For example, if there were 4 loggers that were each to be unloaded once a day starting at 1AM, the user would create a schedule that runs every hour, checks the time and triggers the unload action using the alarm function. The alarm command for the 1:00 unload would be:

ALARM(3ST><0.500, 1.500) The second step consists of creating the FTP command to actually unload the data. The new COPYD command provides a convenient way to unload the data from the logger with number options as to what data is unloaded and how it is formatted. More information on the COPYD command can be found in Part D of the DT8x User’s Manual. For an FTP unload, the basic format of the COPYD is: COPYD START=n FORMAT=m DEST=ftp://name:password@IP_address/pathname Where: n can be a specific time or NEW which will unload only data which has been collected since the last successful unload; m allows the data to be unloaded in text (CSV) or binary (DBD) format. If omitted, the default is CSV; name is the user name for the FTP login; password is the password for the FTP login; IP_address is the address of the FTP server, and pathname is an optional path and filename to save the unloaded data in. If no filename is specified, a file name based on the timestamp will be created. To put it all together, here’s an example to unload the logger at 1AM, copying any new data in CSV format to the FTP server at and putting it in the logger1 directory. In DeTransfer: RG(“B:”,ALARMS:OV:100KB,DATA:NOV:1MB)1H LOGONG GG ALARM(3ST><0.5000,1.5000){[COPYD START=new FORMAT=CSV DEST=ftp://terry:passwd@]}

Here’s a pair of screencaps made in DELogger and then in dEX::

For further information on the bestselling dataTaker DT8X family of data loggers, other dataTaker data logging devices, or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Applications Specialist at (800) 956-4437 or visit the website at

Contact Information:
CAS DataLoggers, Inc.
12628 Chillicothe Road
Chesterland, Ohio 44026
(440) 729-2570
(800) 956-4437