Mitsubishi Electronics QJ71C24/-R2, QJ71C24N, SH-080007 manual 176

7 DATA COMMUNICATIONS USING BIDIRECTIONAL PROTOCOL

MELSEC-Q

7.3.2 Communication data processing when simultaneous transmissions occur

Examples of the Q series C24 communication data processing for various settings of "Simultaneous transmission data valid/invalid designation" by GX Configurator-SC are explained.

(1) Transmission: valid, reception: valid

		2)-1						1)-2
								A
			E	Arbitrary data		Sum check
			N					C
External device			Q			code		K
Q series C24	E							A
		Arbitrary data			Sum check		Time check
	N							C
					code		(timer 1)
	Q							K
	1)-1							2)-2

POINT

When the entire message of 2)-1 was received while transmitting the message of 1)-1 in the illustration.

•The Q series C24 outputs the receive data read request signal of 2)-1 to the PLC CPU after transmitting all 1)-1. (Turns on the X3/XA.)

(2) Transmission: invalid, reception: valid

			2)-1
				E	Arbitrary data		Sum check
				N					Ignores the receive
External device				Q			code
									data of 1)-1.
Q series C24		E						A	(Generates a simultaneous
		N	Arbitrary data			Sum check		C	transmission error.)
		Q				code		K
	1)-1						2)-2

(3) Transmission: valid, reception: invalid

		1)-1						1)-2
									A
			E			Sum check
External device			N	Arbitrary data					C
			Q			code			K
Q series C24	E								Ignores the receive
	N	Arbitrary data			Sum check		Time check		data of 2)-1.
	Q				code		(timer 1)
	1)-1

7 - 25 7 - 25