Programming instructions

31
FLROM (Flash ROM)
FLROM is permanent memory also; the program is retained with no battery
required. FLROM operates similarly to EEPROM, as it is electrically erasable
and can be overwritten many times. Only the FX3U uses Flash ROM.
The chart below details which types of memory modules are available for each
PLC type.
PLC Type RAM EPROM EEPROM FLROM
FX1S
No No 8K w/loader No
FX1N
No No 8K w/loader No
FX2N
8k* 8k 4k, 8k No
FX2NC
No No 4k, 16k, RTC* No
FX3U
No No No
16k, 64k,
64k w/loader*
Notes:
• FX2NC does not have an internal real time clock. A memory module with a real time
clock must be used if real time clock functionality is required
• FX-RAM-8 is only used to extend FX2N memory from 8K to 16K
• FX3U-FLROM-64L must be used if program loader functionality desired on FX3U
The questions to ask are …
1) Which PLC type are you using and what options are available?
2) Do you want the program to be retained, even if battery power is lost?
3) Do you want to be able to change the program easily?