Mitsubishi Electric MELSEC iQ-F FX55-ASL-M, User Manual

Page: 26 / 96

24
4 FUNCTION
4.3 Double Verification
4.3
Double Verification
A double check is an error control system. In this system, cycle data in AnyWireASLINK transmission is recognized as valid
data if the data matches with the data of the last transmission or is ignored as invalid data if the data does not match with the
last data. The double verification ensures reliability of communication.
The double verification is classified into a bit double verification and word double verification.
Overview
■
Bit double verification
If one bit of data is the same between two successive transmission cycles, the data is valid and I/O data is communicated.
■
Word double verification
If one word (16 bits) of data is the same between two successive transmission cycles, the data is valid and I/O data is
communicated.
The bit double verification is suitable for digital I/O type slave modules, which use information in units of bits.
The word double verification is suitable for analog I/O type slave modules, which use information in units of
words.
Setting method
Set the double verification in "Double verification" of "Basic setting". (

Page 52 Double verification)
(1) Transmission cycle (last)
(2) Transmission cycle (current)
(3) I/O data
(4) This data is compared with the verification data (one bit) of the last transmission cycle.
(1) Transmission cycle (last)
(2) Transmission cycle (current)
(3) I/O data
(4) The data is compared with the verification data (one word) of the last transmission cycle.
bit bit
·
bit bit
·
(1)
· ·
(4)
(2)
(3) (3)
word word
·
word word
·
(1)
· ·
(4)
(2)
(3) (3)