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MELSEC-Q
6 PROGRAMMING
6 PROGRAMMING
When diverting the program example introduced in this chapter to the actual system,
fully check that there are no problems in the controllability of the system.
6.1 Programming Precautions
This section explains the precautions in creating programs using data on the network.
6.1.1 Interlock related signals
A list of the interlock signal devices used in the sequence programs is provided below.
See Appendix 2, "List of the Link Special Relays (SB)" and Appendix 3, "List of the Link
Special Registers (SW)" for other explanations, such as the operation status and
setting status of the host and other stations.
When multiple network modules are installed, the interlock signal devices are
refreshed to the devices on the PLC side at 512 points (0
H
to 1FF
H
) intervals according
to the default settings as shown below.
POINT
The Q series uses the link special relays (SB) and the link special registers (SW) in
the entire intelligent function module. Because of this, it is important to manage
SB/SW properly so that duplicate SBs and SWs are not used in a program.
Assignments of the link special relay (SB) and the link special register
(SW) when multiple cards are installed
Mounting
position
Device
1st card 2nd card 3rd card 4th card
SB 0
H
to 1FF
H
200
H
to 3FF
H
400
H
to 5FF
H
600
H
to 7FF
H
SW 0
H
to 1FF
H
200
H
to 3FF
H
400
H
to 5FF
H
600
H
to 7FF
H
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