Header data sent
by the external device

4 SETTINGS AND PROCEDURES PRIOR TO OPERATION

MELSEC-Q

(Procedure 5) Ending the loopback test

Perform the following procedure according to the function used, and start data communication.

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

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

An example of control procedure when the TT command is used in the loopback test mentioned in Procedure 3.

(Station number: 00, sum check code: Yes)

TT (ACPU common command)

Two characters (hexadecimal) … Designate the number of characters (1 to 254) of return data to be sent immediately afterward.

Designate with a text string consisting of "0" to "9" and "A" to "F" (capital letter)

(Data name)

E

StationNo.

PCNo.

Command

N

 

 

 

 

 

 

 

External

Q

 

 

 

device side

 

H L

H L

 

(Example)

 

0 0

F F

T T

 

 

 

 

 

05H

30H 30H

46H 46H

54H 54H

 

 

 

 

 

Messagewait

Characterlength

Loopback data

 

data with the

 

 

 

length given

 

 

 

 

 

by Character

 

 

 

H L

 

length

 

 

 

 

 

 

 

 

 

 

0 0 5 A B C D E

30H 30H 35H 41H42H 43H 44H45H

 

 

(In case of format 1)

Sum check

code

 

Two characters (hexadecimal)

HL

7 8

37H 38H

(Data name)

PLC CPU side

(Example)

Character A part

Becomes the

same data

S

No.Station

No.PC

lengthCharacter

Loopback data

 

 

 

 

 

data with the

 

 

T

 

 

 

 

length given

 

 

 

 

 

 

by Character

 

 

 

 

 

 

 

length

 

 

 

 

 

 

 

 

XH L H L H L

0 0 F F 0 5 A B C D E

02H 30H 30H 46H 46H 30H 35H41H42H 43H 44H 45H

ESum check

code

T

X H L A 3

03H 41H 33H

Header data to be sent by

Character B part

the PLC CPU

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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