5DATA COMMUNICATION USING THE MELSEC COMMUNICATION PROTOCOL

MELSEC-Q

(2) System settings using the GX Configurator-SC

When it is necessary to change the default values registered in the Q series C24, perform the settings as indicated in Chapter 8 and register these to the flash ROM in the Q series C24.

•MC protocol system setting

•Transmission control and others system setting

POINT

To write from the external device to the intelligent function module installed in the MELSECNET/H remote I/O station during communication using the MC protocol, set the "Write allow/prohibit during PLC CPU RUN" in the GX Developer to enable.

5.1.4 Support of multiple CPU system or redundant system

When the external device accesses a QCPU in a multiple CPU system or redundant system, it is possible to selectively access either a control or non-control CPU in the multiple CPU system or a control or standby system CPU or System A or System B CPU in the redundant system by specifying the target QCPU in "Requested module I/O No." of the QnA compatible 4C frame for the MC protocol.

Refer to the Reference Manual for details.

Refer to Chapter 2 of this manual for the system configuration. (Example) When multiple CPU No.1 is specified

E

No.

 

No.

No.

 

 

 

 

N

FrameID

 

Station

Network

Q

 

 

 

 

 

H

L

H

L

H

F

8

0

5

0

05H 46H 38H 30H 35H 30H

PC No.

module

 

Requested

L H L H —

7 0 7 0 3

37H 30H 33H 30H 33H

I/O No.

Requested module station No.

Self-station No.

 

 

 

Command

 

 

 

 

Sub command

Device code

 

 

 

 

Head device

 

 

 

 

 

 

 

Number of device points

 

 

Sum check code

— L

H L

H L

H — — L

H — — L

 

 

 

H — — — — L

H — — L

H L

E 0

0 0

0 0

0 4 0 1

0 0 0 1

X

0 0 0 0 4 0

0 0 0 5

3 6

45H

 

30H

30H

 

30H

30H

 

30H

30H

 

34H

 

30H

 

31H

30H

 

30H

 

30H

 

31H

58H

 

2AH

30H

 

30H

 

30H

 

30H

 

34H

 

30H

30H

 

30H

 

30H

 

35H

33H

 

36H

(Command massage of the QnA compatible 4C frame format 1)

REMARK

•When using the Q series C24 in a multiple CPU system, it is necessary to specify the QCPU that controls the Q series C24 (hereinafter referred to as the control PLC) using GX Developer.

•It is also possible to mount a Q series C24 of function version A in a multiple CPU system. In this case, it is only possible to access the control PLC (PLC No.1).

•It is only possible to access the control PLC if data is communicated by means of frames other than the QnA compatible 4C frame.

5 - 3

5 - 3