Mitsubishi MELSEC Q Series Reference Manual page 313

3 - 253
3 WHEN COMMUNICATING USING THE QnA COMPATIBLE 3E/3C/4C FRAMES OR 4E FRAME
(2) Format 5
(a) When the "Word/byte units designation" in GX Works2 or GX Configurator-
SC is set to "0" (word units)
The following diagram shows the control procedure when two words are
designated as transmission data.
POINT
The number of bytes in the transmission data section of the on-demand data is the
data length  2.
(Two bytes are used for one word of data.)
3- 253