6DATA COMMUNICATION USING THE NON PROCEDURE PROTOCOL MELSEC-Q

If the next data (LF, etc.) is not received within the time set in the non reception monitoring time (timer 0) after CR is received, the Q series C24 stores the received data up to CR to the buffer memory receive data storage area and turns on the following signals to the PLC CPU. When non procedure and non reception monitoring time format is 0:

Reception abnormal detection signal (X4/XB)

When non procedure and non reception monitoring time format is 1:

Reception data read request signal (X3/XA) 1

Timer 0

External deviceC set time

R

Q series C24

( 2)

 

Reception abnormal detection signal

[Format is 0]

(X4/XB)

Reception data read reqest signal

[Format is 1]

(X3/XA)

1 In non procedure protocol, a message is received by the increase in non reception monitoring time (timer 0) if the received complete code and the received data count are not decided.

For the non procedure protocol at the non reception monitoring time format, see Chapter 6 of the User’s Manual (Application).

2 CR is included as 1 byte of data included in the message.

2)When the receive complete code is changed and an arbitrary code is designated (00H designated)

(User defined receive complete code data is added to the end of the message and sent from the external device).

When the Q series C24 receives the receive complete code data changed by the user, it stores the receive data up to the receive complete code to the buffer memory receive area and turned on the read request signal to the PLC CPU.

Receive complete code data

External device

Q series C24

Reception data request signal

(X3/XA)

3)When receive complete code not designated (FFFFH designated) Reading by received data count is enabled.

See (2) for a description of reading by received data count.

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