RAD Data comm HCD-E1 - Manual (Page 66)

Chapter 3 - Front Panel Operating Instructions HCD-E1 Installation & Operation Manual
3-8 Configuration Parameters
Table 3-2 System Parameters
Designation Function Values Configuration Guidelines
CLK MASTER* Selects the master
timing reference. INT Internal oscillator is selected
SL Locked to the recovered receive clock of the E1 sublink.
CH1 or CH2 Locked to the external clock supplied to the
corresponding data channel, provided the channel
timing mode is DTE2.
Default: INT
Select SL for connection to carrier lines.
For a point-to-point application with
standalone equipment at both link
ends, you can also select INT.
Prior to setting CLK MASTER to CH1 or
CH2, you must set the timing mode of
the corresponding channel to DTE2
and assign at least one time slot (see
Table 3-5, Channel Parameters, or the
DEF CH command in Chapter 4).
Note: When HCD-E1 is configured as a remote unit, the CLK MASTER parameter doesn’t appear at all. The clock is always locked to the
recovered receive clock of the HDSL line. This locks the outgoing timings of the E1 port and data channels to the timing of the HDSL
signal. If both lines operate normally, HCD-E1 uses the recovered clock of line A (line 1); if line 1 fails, HCD-E1 automatically switches to
the recovered clock of line 2.
CLK_FBACK *
Selects the
alternate (fallback)
system timing
reference, for use
in case the master
reference fails. NONE No fallback source is used. In this case, the
internal oscillator is automatically selected
when the master reference fails.
SL Locked to the recovered E1 sublink receive clock.
CH1 or CH2 Locked to the external clock supplied to the
corresponding user data channel, provided the
channel timing mode is DTE2
Default: NONE
Select a source different from that
selected as master. To disable switching
to the fallback source, select NONE. In
this case, the default fallback clock
source is the HCD-E1 internal clock
oscillator.
Prior to setting CLK_FBACK to CH1 or
CH2, you must set the timing mode of
the corresponding channel to DTE2
and assign at least one time slot.
HCD TYPE Displays HCD-E1
configuration
mode CENTRAL HCD-E1 configured as central unit
REMOTE HCD-E1 configured as remote unit