RAD Data comm ASM-20 operation manual INT/RCV Mode, Modem B, Odem a Odem B

ASM-20Installation and Operation Manual Appendix B. IR-G.703 Codirectional Interface (64 kbps)

This mode corresponds to the modem clock working in the EXT mode.

Modem A Modem B

	IR -G .7 03 M odu le
	T X D a ta	D a ta		T X	R X
	C lo ck
		C L K
G .7 03	R e cove ry
	C lo ck
C o d ire ctio nal		F IF O
	O u t
6 4 kbp s n etw ork					C lo ck
		D a ta
					R e cove ry
	R X D a ta		C lo ck	R X	T X
Tim in g S ou rce			R e cove ry
		C lo ck In
	F IF O
	E X T C lock M od e				R C V C lock M od e

Figure B-3 IR-G.703 EXT Mode Timing Block

B.4 INT/RCV Mode

This mode is used in applications where the G.703 codirectional 64 kbps equipment connected to the modem recovers the clock signal from the modem link. This mode is used mainly when the attached equipment has a G.703 codirectional interface, but is not able to produce clock signals. The module has a 8-bit FIFO buffer to compensate for the phase delay introduced by the G.703 device. Figure B-4illustrates the buffer connection and the required application setup.

This mode corresponds to the modem clock working in the INT or RCV mode.

INT or RCV Clock M ode

DTE

side

M odem A			M odem B
	LINK				G .703
	side				side
				IR -G .703 M odule
	TX	R X	Clock	Data	RX Data
				CLK
EXT, INT or RCV			Recovery
			Clock
Clock M ode
			O ut	FIFO
(Depending on the					TX Data
	RX	TX		Data
attached network)
				Clock
				Recovery
			FIFO	Clock In
			INT/RCV Clock M ode

Equipment with G .703 interface

Figure B-4 IR-G.703 INT/RCV Mode Timing Block

INT/RCV Mode B-3