MELSEC-Q SRAM Memory Card Technical Bulletin

This technical bulletin details a change in the write protect switch color (from black to white) for SRAM memory cards in the MELSEC-Q series, effective from late 2012. It also outlines precautions for battery error detection failures that may occur with older SRAM cards (manufacturer control numbers "D" to "J" for Q2MEM-1MBS and "C" to "J" for Q2MEM-2MBS), including scenarios where a battery error is not detected and data loss can occur if the controller is powered off.