8. microSD memory card8.1 Automatic booting from the card8.1 Automatic booting from the cardYou can boot an easyE4 base device from the memory card.To be able to do this, the following prerequisites must be met:l The microSD memory card must contain at least one compiled PRG program.l One of the programs must have been set as the starting program, i.e., the microSDmemory card must contain a BOOT.TXT file.l If there is a program on the base device already, the Allow overwriting via cardoption must be enabled in the program.If all these prerequisites are met, the device will boot from the card as follows:Insert the memory card while the device is de-energized.Switch on the supply voltage.Since the RUN start option is enabled by default, the device will automaticallyswitch to RUN mode.As soon as the easyE4 device switches to RUN mode, it will check whether there is aprogram in its internal memory. If there are none, the following step will be skipped.If there is one, the device will check whether the following option is enabled in Projectview/System settings tab/Memory card / device ID section/Program/device ID:Allow overwriting via card – please refer to → "System settings tab" as well.If this option is enabled, the starting program specified in the BOOT.TXT file will becopied from the card to the internal device memory and run.The steps carried out when the device is turned on are shown in detail in the cor-responding flowchart – please refer to → "Overview of switch-on behavior", page 85.Meeting the applicable prerequisitesThere are three different ways to prepare a microSD memory card for booting. Fol-lowing is a description:1. Preparing the card in the PC for booting with easySoft 7The microSD memory card must be inserted into a slot on the PC and written tofrom there.2. Preparing the card in the device for booting with easySoft 7The microSD memory card is already in the device and is written to from the PC.3. Preparing the card for booting on the device itselfThe microSD memory card is already in the device and is prepared for bootingon the device itself. easySoft 7 is not needed in this case.8.1.1 Preparing the card in the PC for booting with easySoft 7Only possible with easySoft 7.488 easyE4 11/18 MN050009 EN www.eaton.com
