Mitsubishi Electronics MELSEC-F Manuel D’Utilisation

5 Buffer Memory (BFM)

FX

3G

/FX

3U

/FX

3UC

 PLC User's Manual - Analog Control Edition

FX

3U

-4AD/FX

3UC

-4AD (4-channel Analog Input)

If data is written to BFM #0, #19, #21, #22, #125 to #129, or #198, the data will also be written to the 4AD
EEPROM.

→ For a detailed description of caution regarding EEPROM writing, refer to Subsection 5.4.1.

Use this function to automatically transfer the upper/lower limit error status data (BFM #26) to the data
register specified in BFM #126.
When the upper/lower limit error is detected, data will be automatically transferred from the 4AD to the PLC.
For this reason, the PLC does not need any program for reading the data, and the scanning time of the PLC
can be shortened.

→ For a detailed description of the upper/lower limit error status data (BFM #26),

• If a data register is already specified for the other automatic transfer functions, do not specify the same 

data register.

• Be sure to turn on the upper/lower limit error status data automatic transfer function (b5 of BFM #22) and 

the upper/lower limit detection function (b1 of BFM #22).

• The data written to BFM #126 will be retained in the EEPROM.

If data is written to BFM #0, #19, #21, #22, #125 to #129, or #198, the data will also be written to the 4AD
EEPROM.

→ For a detailed description of caution regarding EEPROM writing, refer to Subsection 5.4.1.

D208

Upper/lower limit error status data in BFM #26