4 SETTINGS AND PROCEDURES PRIOR TO OPERATION

(Procedure 4) Checking the results of an individual loopback test

MELSEC-Q

(1)This test is performed repeatedly. When the ERR LED is off, the test is being executed normally.

(2)The test is completed with an error when the ERR LED is lit. Check the error description on one of the following screens. (The ERR LED is lit upon error occurrence, and the test is completed.)

•The "Monitor/test others" screen of GX Configurator-SC (see Section 8.6.9)

•The buffer memory monitor screen of GX Developer (see the GX Developer Manual for operation method)

When checking for errors in the buffer memory monitor screen of GX Developer, monitor the LED ON status storage area (address CH1: 201H, CH2: 202H).

Check the error descriptions on the screens by bit-decoding the monitored value (16-bit integer). Each bit corresponds to the following error description.

Buffer memory monitored

 

Description when corresponding

 

Address

CH1 side

 

CH2 side

Corrective action

 

bit is on

Bit location

201H

 

202H

 

 

 

 

b0 to b3

—

 

—

—

 

 

 

 

Error occurrence in the CPU module.

Remove errors occurring in the CPU

 

 

 

 

module.

 

 

 

 

Not enough power supply capacity.

Examine the power supply capacity.

b4

C/N

 

—

Module is not mounted correctly.

Reinstall the module properly.

 

Error occurrence in the base unit,

Check each module and remove the

 

 

 

 

 

 

 

 

cause of the error.

 

 

 

 

extension cable, CPU module, or the

 

 

 

 

Reconnect the cable correctly.

 

 

 

 

Q series C24.

Reinstall the module correctly.

 

 

 

 

 

b5 to b13

—

 

—

—

b14

—

 

CH2 ERR

CH2 side communication error

Reconnect the cable correctly.

 

 

 

 

b15

 

CH1 ERR

CH1 side communication error

Examine the test wiring connection.

 

 

 

 

 

 

 

 

 

 

 

(Procedure 5) Ending individual station loopback test

(1) Perform the following procedures after checking normal completion/abnormal completion of the test result.

Normal completion : Perform operation (2) to finish the test.

Upon error occurrence : Remove the cause of the error according to the corrective action specified in the table above, and test again.

(2)Perform the ending procedure for individual station loopback test

1)Follow the procedure in Section 4.7.1 to perform a ROM/RAM/switch test.

2)Perform the following procedure to end the test and start data communication with an external device.

•Set the switch settings on GX Developer according to the procedure specified in Section 4.5.2.

•Turn off the power to the station on which the Q series C24 is installed and connect the communication cable with the external device.

•Turn on the power to the station on which the Q series C24 is installed.

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