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MELSEC-Q
4 SETTINGS AND PROCEDURES PRIOR TO OPERATION
Incorrect insertion
Inserted horizontally.
(e) If data cannot be communicated with the external device at all, the polarity of
the external device could be wrong and should be checked again. If the
polarities of the Q series C24 and the external device do not match, reverse
the polarity of each signal on either device side and connect the devices with
the cable; this may enable the data to be communicated.
POINT
(1) For terminal resistor setting/connection described in this section, when the RS-
232 to RS-422 converters or similar device is used at the external device at
both ends of the circuit, a terminal resistor must be set, or connected, at the
converter.
(2) When using the RS-232 to RS-422 converters to connect the external devices
and the Q series C24, use a converter that is compatible with the external
device and programmable controller CPU system configuration (1:1, 1:n, m:n).
(3) Device connected to the Q series C24 RS-422/485 interface must be
standardized as RS-422 or RS-485, including 1:n, n:1 and m:n connections.
(2) Connection examples
(a) External device and Q series C24 with 1:1 system configuration
Terminal
resistor
R
R
Q series C24
Signal name
SDA
SDB
RDA
RDB
External device
RDA
RDB
SDA
SDB
RSA
RSB
CSA
CSB
SG
FG
SG
FG
FG
Terminal
resistor
Signal name
Summary of Contents for MELSEC QJ71C24
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Page 103: ...3 42 3 42 MELSEC Q 3 SPECIFICATIONS MEMO ...
Page 177: ...6 33 6 33 MELSEC Q 6 DATA COMMUNICATION USING THE NON PROCEDURE PROTOCOL MEMO ...
Page 397: ...App 24 App 24 MELSEC Q APPENDIXES Connection example 3 Connection example 4 ...
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