Aim ACE1553-3U-4, Hardware Manual

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ACE1553-3U-4 Hardware Manual 13
In network emulation mode, the MILbus emulation circuitry emulates a transformer-coupled
network without the use of MILbus couplers (using a resistor network). Thus, an external dual-
redundant MIL-STD-1553 Terminal can be directly connected to the module.
Figure 3.4 shows the typical MILbus output amplitude function depending on the voltage on the
Vcontrol input which can be derived from the following formula:
256
2
/
N
V V
ref B outA
  
Where N is the 8 bit digital input value and V
ref
the voltage on the Reference pin.
The input value in this formula is the digital 8 bit value (0..255) written to the onboard digital to
analogue converters. The 100% value depends on the transceiver type, the coupling mode and
the bus termination. The output value is approximatively 20Volts for a transformer coupled stub
terminated with 70Ω.
Figure 3.4: MILbus Amplitude vs. V
control
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5
Vcontrol [V]
M
IL
B
u
s
V
o
u
t[
%
]