Nautel XR12 Troubleshooting Manual

Also see for XR12: Installation manual Operation and maintenance manual Preinstallation manual

Contents

XR12 Troubleshooting Manual Reading Electrical SchematicsPage 5-2 Issue 3.0 2009-07-28Unique symbolsNautel uses unique symbols on electrical schematics to describe logic (two-state) signals. Thesesignals differ from single-state signals or analog signals that may have multiple values.Type of inputs and outputsOn electrical schematics, names used to describe logic (two-state) input and output signals areprefixed with a # symbol.Logic level conventionThe # symbol prefix identifies an input or output signal that has two distinct states: high and low.The suffix on the signal name identifies the active (true) state of the signal. The high (+ suffix) is themore positive of the two levels used to represent the logic states. The low (- suffix) is the less positiveof 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 diagramsEach illustration in this section is identified by a number that is both the figure number and the pagenumber. The numbers are assigned sequentially and are prefixed by the letters SD. The electricalschematics and logic diagrams included in this section are listed in Table 5.1 on page 5-5.