AS41 T1/E1 Autoswitch
G.703 / 704/ 1.544 MHz / 2.048 MHz
Autoswitch for the GPU frame
The AS41 is an automatic and manual 4 into 1 data switch intended for use in the GPU frame. The switch runs in two distinct modes, E1 G703/704 or 2.048 MHz mode, selected by a jumper on the PCB.
When the G703/704 mode is selected, input signals are routed to four independent transformer balanced receiver channels, compliant with ITU G.703 Pulse Mask Template for 2.048Mbps (E1) Rates. Each channel performs the receiver functions necessary to provide a LOS indication signal with thresholds and delay that comply with the ITU G.775 requirements. The LOS signals are sent to the microprocessor to facilitate auto switching.
When the 2.048 MHz mode is selected, input signals are routed to four independent TTL compatible input circuits with peak detectors and comparators with fixed thresholds and fast attack and release times. The LOS signals are sent to the microprocessor to facilitate auto switching
The data switch circuitry performs active pulse shaping before the selected input signal is routed to the output.
The auto/manual switching function is identical in both modes and has a fast and a slow mode setting. In fast mode, the circuit switches immediately when the input detector declares the input not valid. In slow mode, the circuit will accept an absence of signal for 1 second before declaring the input not valid. If the signal returns before the 1 second time out, the switch will not initiate an input jump.
