Mitsubishi Electric MELSEC iQ-R Series Reference Manual page 48

Response message format (from slave to master)
■ When completed successfully
N shown below is the total of the device data (n1 + ... + nm).
Function code
Number of
response data
bytes
m×2+N×2
14H
■ When completed with an error
Function code Data
Exception code
94H
3 MODBUS STANDARD FUNCTION DETAILS
46
3.14 Read File Record (FC: 14H) (SC: 06H)
Number of Reference
read bytes number
n1×2+1
(06H)
(H)
Number of response data bytes m×2+N×2
Reference
Number of
number
read bytes
nm×2+1
(06H)
Data
Sub-request 1
Device data 1
(L)
Number of read bytes n1×2+1
Data
Sub-request m
Device data 1
(H) (L)
Number of read bytes nm×2+1
Number of response data bytes m×2+N×2
Device data n1
(H) (L)
Device data nm
(H) (L)