Double Verification - Mitsubishi Electric MELSEC iQ-R AnyWireASLINK User Manual

1.2

Double Verification

A double verification 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.
There are two types of double verification: double verification in 1-bit unit and double verification in 16-bit unit.
Overview
■Double verification in 1-bit unit
If one bit of data is the same between two successive transmission cycles, the data is valid and I/O data is communicated.
(1)
bit bit
(3)
(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.
■Double verification in 16-bit unit
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.
(1)
word word
(3)
(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.
The double verification in 1-bit unit is suitable for slave modules that handle information in units of bits such as
ASLINKER.
The double verification in 16-bit unit is suitable for slave modules that handle information in units of 16 bits
such as ASLINKAMP (analog input module).
Setting method
Set the double verification of bit data in "Double verification" of "Basic setting". ( Page 50 Bit data double verification
setting)
The double verification of word data does not need any setting.
(2)
bit bit
(3)
(4)
(2)
word word
(3)
(4)
1 FUNCTIONS
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1.2 Double Verification
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