Dicon VX500, Руководство по эксплуатации, Страница: 8 / 24

91500 Revision B
8 DiCon Fiberoptics VX500 Fiberoptic Switch
One way to reset the switch is to cycle the supply power to the switch. The switch returns
to the reset position following the initial application of power to the POWER pin (see “Start-
ing the Switch” on page 7).
To return the switch to the reset position without interrupting the supply power, set the
RESET input to low and apply a STROBE pulse. The RESET input is latched by the falling
edge of the STROBE signal, respecting hold, setup, and pulse width constraints (see
Table 6). The BUSY output remains high until the reset operation is complete and the
device is ready to receive additional instructions.
Losing Power to the Switch
If the supply power is interrupted the switch
does not
latch in its current position. Instead,
it loses direct fiber-to-fiber alignment, breaking the optical connection. When supply power
is restored the switch automatically restarts, returning to the reset position.
Selecting an Output Channel
To choose a specific channel, set the RESET input to high, set the channel address inputs
(<D4:D0>) to the appropriate value (see Tables 2, 3, 4, and 5), and apply a STROBE pulse.
The inputs are latched by the falling edge of the STROBE signal, respecting hold, setup,
and pulse width constraints (see Table 6). The BUSY output will go high until the STROBE
pulse has ended, the switch operation is complete, and the device is ready to receive addi-
tional instructions. Note that the BUSY signal will remain high until the end of the STROBE
pulse, even if the switch operation is complete and the optical connection is stable.
If the latched value of the channel address (<D4:D0>) is the same as the previous latched
value, the BUSY signal will go high for 60 –80ms even though there is no switch movement.
If the latched value of the channel address (<D4:D0>) indicates an out-of-range position,
the BUSY and ERROR signals will go high for 60–80ms.
The following sections list the switch channel number associated with each data-input set-
ting for simplex 1
×
N, synchronous duplex 1
×
N, 2
×
N blocking, and 2
×
N non-blocking
switches, respectively.
Simplex 1
×
N Configurations
The relationship between the optical inputs and outputs in a VX500 simplex 1
×
N switch is
shown in Figure 3.
Figure 3: Simplex 1
×
N Switch Configuration
The arrangement of the fiber pigtails on a VX500 1
×
N switch is shown in Figure 4. The left
diagram applies to switch units with up to 16 output channels. The right diagram applies to
units with 17 –32 output channels.
1
2
3
N
0
1