Station-Based Block Data Assurance For Cyclic Data - Mitsubishi Electric Melsec QJ71LP21 Reference Manual

6 PROGRAMMING

6.2.2 Station-based block data assurance for cyclic data

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Since handshakes are performed between a CPU module and a network module for link
refresh, consistency of cyclic data is assured for each station (link data separation
prevention per station
As shown below, set the send and receive parameters as needed.
These settings can be made using the common parameters (supplementary settings)
only for the control station.
The default varies depending on the network type.
Network type
MELSECNET/H mode
MELSECNET/10 mode
MELSECNET/H Extended mode
Network range assignments
By selecting both [Block send data assurance per station] and [Block receive data
assurance per station], an interlock for the link data between the stations to be set
becomes unnecessary.
CPU module device W
Updated portion
Refresh A
of refresh A
Updated portion
Refresh B
of refresh B
Updated portion
Refresh C
of refresh C
<Precautions>
(1) In order to enable the station-based block data assurance, refresh parameters
must be set. (Refer to Section 5.7.)
(2) Station-based block data assurance for cyclic data is not required for normal
stations.
POINT
(1) The station-based block data assurance applies only to the refresh
processing. To use the direct access (J \
provide interlocks in the programs.
(2) For the transmission delay time calculation for the case where the Block
send/receive data assurance per station is enabled, refer to Section 3.3.2 (1) (a)
POINT.
(3) When the network is set up in the MELSECNET/10 mode, station-based
block data assurance is valid only for stations with QCPU. For those with
ACPU/QnACPU, provide interlocks in the program referring to the program
example in Section 6.2.3.
1: The separation prevention refers to a prevention of link data with double
word precision (32 bits), such as the current value of the positioning module,
from being separated into new data and old data in one word (16 bits) units
due to the cyclic transmission timing.
1).
"No" for both send and receive
"Yes" for both send and receive
Supplementary settings
Network module LW
Station number 1
Station number 2
(Host)
Station number 3
Station number 4
Default
Data assured
Data assured
Data assured
Data assured
designation) of the link devices,
MELSEC-Q
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