12778474-002-2 Revision F – March 2004
TSG-3800 User’s Guide 217
Output Modules
AMI 10-Output Module
There can also be two pairs of clocks connected to the module, depending upon the
Frame Generator settings. Each pair consists of A and B clocks, coming from
Frame Generator A and Frame Generator B, respectively. These are identical
clocks, providing redundant clocks to the module.
Rocker switch S1 and MUX 2 control the selection of the A/B clock pair used by the
module to generate its outputs. When the CLKSEL switch is pressed on the “0” side,
it causes MUX 2 to select the CLK1 inputs. When the “1 side is pressed, the CLK2
inputs are selected.
A third rocker switch in S1, labeled TCLKSEL, configures the output drivers for the
frequency of the clock selected by MUX 2. When this switch is pressed on the “0”
side, the drivers are configured for a clock of 1.544 MHz (T1); when the “1” side is
pressed, the drivers are configured for 2.048 MHz (E1).
The shape of the output waveform is controlled by the output drivers, and by the
three remaining switches in S1, labeled LEN0, LEN1, and LEN2 (TCLKSEL = 0),
that are connected to the drivers. Depending upon the settings of these switches,
the output drivers will produce the appropriate output pulse shape to meet the
DSX-1 or CSU templates, over a wide variety of cable types and lengths.
When TCLKSEL is set to 1, the E1 mode is enabled. In this mode only one output
pulse shape is available. LEN0, LEN1, and LEN2 may be in any state, except all
zeros. A safe setting for these three switches is OFF.
MUX 3 selects either the A-input and A-clock, or the B-input and B-clock (normally
A), from the input and clock pairs selected by MUX 1 and MUX 2. These signals are
used by the output buffers to generate the desired outputs.
If the A input or A clock fails, the module detects this and switches to the B signals
automatically. The INPUT FAULT A LED (yellow) is turned on and the CPU module
is notified. The module continues to operate from the B inputs, with a fault indicated,
until it is replaced or the A inputs return. If the A inputs return, the module will
automatically switch back to them. This is the preferred operating condition.
A failure of the B signals causes the module to turn on the INPUT FAULT B LED
(yellow) and to notify the CPU module. There is no automatic switchover to the A
inputs, since the module will already be using them if they are good. The module
can be made to change its reference, through the CPU module.
The module checks the outputs to confirm signal presence. If an output fails, the
OUTPUT FAULT LED (red) on the front panel is turned on. The CPU module is also
informed of this condition, through the Frame Generator module. The relay, through
which the output is connected to the rear panel, is de-energized, disconnecting the
failed output on this module from the corresponding output on the backup module.
When an output fails, there may be a temporary loss of the corresponding signal on
the backup module. However, this is cleared automatically within one second, when
the CPU attempts to clear the faults generated by both modules. The other outputs
are not affected.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com