4 SETTINGS AND PROCEDURES PRIOR TO OPERATION
4.7.2 Individual station loopback test
The individual station loopback test checks the operation of the communication function of the Q series C24.
Follow the procedure below to perform an individual station loopback test. (Procedure 1) Connecting cable
(1)Connect cables to two interfaces as follows.
•Connect cables to the
•Connect cables to the
Q series C24 side |
Q series C24 side
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CD | 1 |
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RD (RXD) | 2 |
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SD (TXD) | 3 |
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ER (DTR) | 4 |
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SG | 5 |
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DR (DSR) | 6 |
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RS (RTS) | 7 |
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CS (CTS) | 8 |
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RI (CI) | 9 |
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Signal name
SDA
SDB
RDA
RDB
SG
FG
FG
Cable connection
(Procedure 2) Communication protocol setting and transmission setting (see Section 4.5.2)
(1)Set the communication protocol setting to FH (individual station loopback test) for both interfaces.
(2)Set each transmission setting of the two interfaces according to the transmission specification for data communication with an external device.
(Procedure 3) Performing the individual station loopback test
(1)Set the PLC CPU to STOP status.
(2)Restart the PLC CPU station or reset the CPU. The test starts automatically in about one second.
(3)For the Q series C24, perform the following tests in sequence and repeat them (one test cycle takes approximately one second).
End testing when all test results become abnormal.
1)Check communication with the PLC CPU
Read and check the model type of the PLC CPU.
2)Check transmission and reception functions of the interface Perform communication while changing data.
(4)The LED corresponding to a test item flashes when the test starts.
•The CH1 NEU LEDs flash when checking communication with the PLC CPU.
•The SD and RD LEDs of the interface being tested flash when checking the communication functions of each interface.
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