ASM-20 Installation and Operation Manual Appendix B. IR-G.703 Codirectional Interface (64 kbps)
6/4/99 13:17 INT/RCV Mode B-3
This mode corresponds to the modem clock working in the EXT mode.
Timing Source
TX Da ta TX
TX
RX
RX
RX Data
G.703
Codirectional
64 kbps network
FIFO
EXT Clock Mode RCV Clock Mode
Clock In
Clock
Out
Modem A Modem B
Clock
Recovery
Data
Data
CLK
Clock
Recovery
FIFO
IR-G.70 3 M odule
Clock
Recovery
Figure B-3 IR-G.703 EXT Mode Timing Block
B.4 INT/RCV ModeThis 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-4 illustrates the buffer connection
and the required application setup.
This mode corresponds to the modem clock working in the INT or RCV
mode.
TX
RX RX Data
TX Data
TX
RX
INT or RCV
Clock Mode EXT, INT or RCV
Clock Mode
(Dependin
g
on the
attached network)
Modem A
Equipment
with G.703
interfac e
LINK
side G.703
side
DTE
side
INT/RCV Clock Mode
Modem B
Clock In
Clock
Out
IR-G.70 3 Module
Data
Clock
Recovery
FIFO
Clock
Recovery
Data
CLK
FIFO