Product Manual - DM991 Series V Family - 204.4092.08
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The external clock is provided by the DTE through the CT113 in the digital interface or recovered through
the G.703 signal, depending on which interface is enabled. The DTE should provide it with ±50ppm
precision for connection in plesiochronous mode and ±32ppm for connection in synchronous (to operate
according to the G.991.2 rule). When operating with external clock, the modem automatically switches to
internal clock in case of flaw in the external clock source, but errors can occur in the transmission
sequence during the commuting.
The external clock with CT104 synched according to CT113 (External RX in Table 19) operates as
external clock, being that in this mode the data (CT104) of the V.35 or V.36/V.11 interface are also
transmitted to the DTE synched by the external clock CT113. The commuting to internal clock is automatic
during the period in which there is clock loss in the CT113, but this can cause errors in the transmission
sequence during the commuting. If the G.703 interface is enabled, the operation is the same as external
clock.
8.3. LDR Enabling (DIP A8)
When ON, allows the LDR request to be accepted.
When OFF, rejects the LDR request.
8.4. Cross-Connect CAS (DIP B1)
When ON, enables the E1 interface CAS transmission to the line.
When OFF, CAS synch is not generated or verified.
This DIP has no function when DIP B4 or DIP B7 is set to ON.
8.5. Timeslot 16 Enabling (DIP B2)
When ON, enables the data transmission through timeslot 16 of the E1 interface.
When OFF, disables the data transmission through timeslot 16 of the E1 interface.
This DIP has no function when DIP B4 or DIP B7 is set to ON.
8.6. CRC4 Enabling (DIP B3)
When ON, enables the generation and verification of CRC4 synch on the E1 interface.
When OFF, disables the generation and verification of CRC4 synch on the E1 interface.
This DIP has no function when DIP B4 or DIP B7 is set to ON.
8.7. E1/Digital interface selection (DIP B4)
When ON, enables the digital interface and disables the E1 interface.
When OFF, enables the E1 interface and disables the digital interface.
To use both interfaces simultaneously it is necessary to set the configurations through the remote
management or the terminal. For that, DIP B6 must be set to ON or configured for the converter mode
(DIP B7).
This DIP has no function when DIP B7 is set to ON.
In the converter mode the LDR test will be on V.35 interface
Summary of Contents for DM991C
Page 1: ...DM991 SERIES V DM991C DM991CE DM991S DM991SE PRODUCT MANUAL 204 4092 08 rev 08 Date 8 12 2008 ...
Page 66: ...Product Manual DM991 Series V Family 204 4092 08 66 Figure 31 LDL Test Converter Mode ...
Page 89: ...Phone 55 51 3358 0100 Support 55 51 3358 0122 Fax 55 51 3358 0101 www datacom ind br ...
