Mitsubishi 00JCPU User Manual page 430

Instead of using the intelligent function module device in the sequence program twice or more to write or read buffer memory
data, using the FROM or TO instruction once in one place can increase the processing speed.
Remark
1) For buffer memory addresses and applications, refer to the manual for each intelligent function module/special
function module.
2) For the FROM and TO instructions, refer to the following.
9 - 55
Figure 9.58 Writing data using the intelligent function module device multiple times
Figure 9.59 Writing data using the TO instruction once in the program
MELSEC-Q/L Programming Manual (Common Instruction)
Writes data to a device
such as data register (D)
Writes data once in the program