Nautel VX150, Troubleshooting Manual, Page: 138 / 182

VX150 TO VX2 TROUBLESHOOTING MANUAL ELECTRICAL SCHEMATICS
PAGE 3.4.2 VERSION 2.0 2023-04-20
Unique Symbols
Nautel uses unique symbols on electrical schematics to describe logic (two-state) signals. These signals
differ from single-state signals or analog signals that may have multiple values.
Type of Inputs and Outputs
On electrical schematics, names used to describe logic (two-state) input and output signals are prefixed
with a
#
symbol.
Logic Level Convention
The # prefix identifies an input or output signal that has two distinct states: high and low .
The suffix on an input or output signal name identifies the active (true) state of the signal. The high
suffix (+) indicates the more positive of the two levels used to represent the logic states. The low suffix
(-) indicates the less positive of the two levels.
Two types of logic, positive and negative, may be represented on a particular schematic. In positive
logic,
high represents the active (true) state, and low represents the inactive (false) state. In negative
logic, low represents the active (true) state, and high represents the inactive (false) state.
Identifying Schematic Diagrams
Each electrical schematic in this section is identified by a number that is both the figure number and the
page number. The numbers are assigned sequentially are prefixed by the letters
SD
. The electrical
schematics and logic diagrams included in this section are listed in Table 3.4.1 on page 3.4.5 .