4 SETTINGS AND PROCEDURES PRIOR TO OPERATION

MELSEC-Q

(a)Transmission setting (CH1 side: switch 1 (lower level); CH2 side: switch 3 (lower level))

b7

b6

b5

b4

b3

b2

b1

b0

CH1 side

CH2 side

 

Bit

Description

OFF (0)

ON (1)

Remarks

 

 

b0

Operation setting

Independent

Link

Must be set to OFF on CH1

 

 

b1

Data bit

7

8

Parity bit is not included

 

b2

Parity bit

NO

Yes

Vertical parity

 

b3

Even/odd parity

Odd

Even

Valid only when parity bit is set to

 

Yes

 

 

 

 

 

 

b4

Stop bit

1

2

 

b5

Sum check code

NO

Yes

 

b6

Write during RUN

Prohibited

Allowed

 

b7

Setting modifications

Prohibited

Allowed

All items listed in the table should be set to OFF for the interfaces for which "GX Developer connection" is set in the communication protocol setting.

If connecting directly to the GX Developer, it operates with the setting value on the GX developer. (Refer to the description below.)

Transmission setting

Setting description for GX Developer

Operation setting

Independent

Data bit

8

Parity bit

Yes

Even/odd parity

Odd

Stop bit

1

Sum check code

Yes

Write during RUN

Allowed

Setting modifications

Allowed/Prohibited

1)Operation setting

This sets whether to use each of the two Q series C24 interfaces for independent data communication, or to use the two for linked data communication.

The setting and data flow for linked operation is explained in (2).

2)Data bit setting

This sets the bit length for one character in data communicated with an external device according to the specifications of the external device. (When data communication is performed using format 5 of the MC protocol (for binary code communication), it is necessary to set it to 8 bits when processing the sum check code with the bidirectional protocol.)

If 7 bits are set, the data is communicated by ignoring the most significant bit (8th bit).

3)Parity bit setting

This sets whether or not a parity bit (vertical parity) is added for one byte of transmission/receive data, according to the specifications of the external device.

The addition of the parity bit to the transmission data and the checking of the parity bit of receive data are performed by the Q series C24.

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