Reference
3-6
ST2400A SDH Test Set User Manual
In the next menu, when “
OPTICAL
” is selected, the internal APD Receiver will be enabled,
ELECTRICAL
” is selected the APD Receiver will be disabled, electrical input will be
used and the LOS front panel LED will be invalid. If no RX board or no APD Receiver is present
the next menu shown will not be available and “
ELECTRICAL
” output will be automatically
enabled.
TX 2.488 Gb/s ELEC OUTPUT
<OFF> ON
TX Event Trigger Output Menu
Another push of the Setup key will access the
TX EVENT TRIGGER OUTPUT
menu. It is
used to select whether an alarm or an error condition will be used to generate the event trigger
pulse from the rear panel BNC connector. The event trigger is 2.4 Vpeak minimum, with a pulse
width of 25 nS ±10%, and leads the event by less than 1µs. It can be used to synchronize other
equipment, such as an oscilloscope trigger source.The TX Event Trigger Output menu is available
in the Transceiver or Transmitter configurations.
TX EVENT TRIGGER OUTPUT
<ALARM> ERROR
The next menu is available in the Transceiver or Receiver configurations.
RX 2.488 Gb/s INPUT
<OPTICAL> ELECTRICAL
In the next menu, RX Threshold Offset is only available when an APD module is installed in the
ST2400A. RX Threshold Offset is adjustable from -50 to +49. At 0 offset, RX threshold is at
optimal point as determined by the average input signal level.
RX THRESHOLD OFFSET
50
The following menu will appear any time an APD overload occurs, the user must reduce input
power and press “
RESET
” to reset the trip circuitry. The user may choose to ignore this
message and press "BYP" to bypass this menu. However, the APD circuitry will remain disabled
until input power is reduced and the "
RX 2.488 Gb/s Input
" menu is changed to OPTICAL.
RX OPTICS DISABLED
Summary of Contents for ST2400A
Page 7: ...ST2400A SDH Test Set User Manual vii Index I 1...
Page 12: ...General Safety Summary xii ST2400A SDH Test Set User Manual...
Page 13: ...Getting Started...
Page 14: ......
Page 24: ...Operating Basics...
Page 25: ......
Page 44: ...Reference...
Page 45: ......
Page 94: ...Reference ST2400A SDH Test Set User Manual 3 49...
Page 95: ...Appendices...
Page 96: ......
Page 113: ...Specifications SDH ST2400A SDH Test Set User Manual A 17...
Page 134: ...Factory Defaults C 4 ST2400A SDH Test Set User Manual...