I was able to access a memory card in the printer when connected to my computer via USB cable. After I installed the network software, I can no longer access the memory card.
Epson printers and All-In-Ones with integrated network connectivity and memory card slots
When you enabled the network connection, the USB connection was disabled. The printer supports only one connection type at a time: USB, Ethernet cable, or wireless.
To access the memory card slot over a network, set File Sharing Setup to Enable on the printer's control panel and select Network. This setting is available via Network Settings in the Setup menu. You need to select Read Only. To make the memory card writable, set the Share mode to Read/Write.
For help with configuring the network slot for Mac OS X or Windows, please see one of the Related Articles below or refer to your printer's HTML User's Guide; section "Configuring the Network Card Slot" in Home > Networking > Setup Using the Control Panel and OS Functions.