A20B-3900-0060 Fanuc 16i 18i 21i SRAM Module 2MB

For SRAM data in the i series, an ECC check has superseded a parity check in the following editions of the motherboard and boot software. If the motherboard, CPU card, or boot software is replaced with one with a different SRAM data check method, and an SRAM data mismatch occurs, a parity alarm or ECC alarm may occur when the power is switched on, leading to loss of the SRAM data. This problem does not occur if the previous SRAM data restored from a backup copy is used after replacement or if the system is started after all memory clear.