Link Relays (B) - Mitsubishi Electric MELSEC-Q Series User Manual

10 DEVICES

10.2.7 Link relays (B)

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(1) Definition
(a) A link relay is the Basic model QCPU relay used to refresh the Basic model
QCPU from the MELSECNET/H network module's link relay (LB) and to
refresh the MELSECNET/H network module's link relay (LB) from the Basic
model QCPU data.
Basic model QCPU
Link relay
B0
Internal relays or latch relays can be used for data ranges not used by the
MELSECNET/H network system.
• Range where no link relay latch occurs...Internal relay
• Range where link relay latch occurs........Latch relay
(b) There are no restrictions regarding the number of contacts (N/O contacts,
N/C contacts) used in the program.
X0
B0
X1 B0
X2 B0
(2) Using link relays in the network system
In order to use link relays in the network system, a network parameter setting is
required.
REMARK
1) For details regarding the network parameters, refer to the For Qs MELSECNET/H
Network System Reference Manual.
2) The MELSECNET/H Network Module has 16384 link relay points assigned.
Basic model QCPU has 8192 link relay points assigned. When using subsequent
points after Point 8192, change the number of link relay points by using the
Device Setting sheet of the PLC Parameter dialog box.
MELSECNET/H network module
LB0
Link refresh
No restrictions regarding the quantity used.
B0 switches ON at X0 OFF to ON.
SET B0
The link relay (B0) ON can only be used for internal Basic
model QCPU processing, and cannot be output externally.
K20
T0
Y20 B0 ON/OFF information is output from the output module
to an external destination.
B100
B1FFF
Figure 10.7 Link Relay
MELSEC-Q
Link relay
Link refresh setting range
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