4 SETTINGS AND PROCEDURES PRIOR TO OPERATION

MELSEC-Q

(2)Restart the PLC CPU station or reset the CPU. The test starts automatically in about one second.

(3)For the Q series C24, the following tests should be performed once.

1)ROM check

Read the ROM data and verify the sum check.

2)RAM check

Write data to RAM, and read and check it.

3)Switch check

Check whether or not each switch is set within the tolerance range and the operation setting in the transmission settings is set to off.

4)Linked operation setting check (perform this test with the operation setting in the transmission settings of CH2 set to on)

Check to see that the communication protocol setting on CH1 is set to 8H and whether the communication rate setting of each channel is within the tolerance range.

A linked operation setting check is performed when values are set as follows:

• Communication protocol setting on the CH1 side : 8H

• Operation setting in the transmission settings on the CH2 side: bit 8 = ON.

(Procedure 3) Checking results of ROM/RAM/switch tests

(1)The test is completed when the NEU LED on CH1 side is lit (approximately 2 seconds).

(2)The test is completed normally when the ERR LED turns off.

(3)The test is completed with error when the ERR LED turns on. Check the error description in one of the following screens.

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 the operation method)

When checking errors in the buffer memory monitor screen of GX Developer,

monitor the following buffer memory.

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

 

 

 

 

 

 

Address

CH1 side

 

CH2 side

CH1/CH2 side

Description when corresponding bit is on

Corrective action

Bit location

201H

 

202H

203H

 

 

 

 

 

b0

 

 

 

 

 

b1

 

SIO

When linked operation

Transmission setting error

Review setting value

b2

 

PRO

setting

 

Protocol setting error

 

 

(see Section 4.5.2)

b3

 

P/S

When independent

 

Transmission setting error

 

 

 

 

b4

 

C/N

operation setting

 

Protocol setting error

 

 

b5 to b6

 

 

 

 

b7

NEU

 

 

Test completed

 

b8 to b13

 

 

 

 

 

 

 

 

 

CH2 ERR

 

RAM error

(

1)

b14

 

Setting station

Out of the setting station number range

Review setting value

 

 

number

(see Section 4.5.2)

 

 

 

 

 

 

 

b15

 

 

CH1 ERR

 

ROM error

(

1)

1 Consult your nearest dealer.

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