Timing Mode Selections - Patton electronics 1082/F User Manual

The first G.703 modem is in Internal Clock mode. The second modem is
in Receive Recover mode. See Figure 3.
RX
TX
CSU
DTE
RX
TX
CSU
DTE

2.5 TIMING MODE SELECTIONS

Based on the timing arrangements and clock sources mentioned above,
there are two timing modes in which the interface can work. These two
modes select the clock sources mentioned above and determine which
clock gets smoothed.
• Network Timed—This sets the interface to pass the smoothed recov-
ered timing to the modem as XCLK1, with the Rx data as TXD1, and
also to the G.703 Tx side.
• Internal/Receive Recovered—This sets the interface to use the
modem's Tx timing (recovered or internal source) to send the Rx data
(as TXD1) to the modem and to smooth the modem's recovered timing
for transmitting on the G.703 Tx side.
G.703 INTF-
MODEM
TIMED MODE
TX
G.703
RX
TX
G.703
RX
G.703 INTF-
MODEM
TIMED MODE
Figure 3. Network Replacement Configuration
G.703 TX
SMOOTHS
RX MODEM
CLOCK
FIFO
FIFO
SECOND MODEM
G.703 TX SMOOTHS
RX MODEM CLOCK
FIFO
FIFO
SMOOTHED
FIRST MODEM
10
HOST
MODEM -
RECOVERED
TIMING
RX
TX
RX
2 Wire
TX
HOST
MODEM -
INTERNAL
TIMING