Delta Electronics Human Machine Interface DOP-A Series - Manual (Page 314)

Appendix B USB Flash Drive Function|ScrEdit Software User Manual
Revision Apr. 30th, 2007, 2007PDD23000002 B-9
Upgrade Firmware:
The user can press this icon to upgrade the HMI firmware via USB flash drive
immediately and compare the firmware version through the screen directly.
Please refer to the following figure.