TM 11-6625-3145-14
Section 4-318/338 Service
THEORY OF OPERATION
SECTION ORGANIZATION
This section contains a functional description of the circuitry used in the 318 and 338 Logic Analyzers. It is divided into two
sub-sections:
General System Description and Detailed Circuit Description
. Block diagrams, wiring diagrams, and detailed
schematics for the 318 and 338 are found in the tabbed
Diagrams
section at the rear of this manual.
Use the 318/338 Block Diagrams in the
Diagrams
section with the
General System Description
part of this section. Blocks
on the block diagrams correspond to sub-headings in the
General System Description
. Use the system schematics in
conjunction with the
Detailed Circuit Description
part of this section. Schematics are referenced to section headings and
sub-headings by corresponding numbers in diamonds. This section and the block diagrams and schematics in the
Diagrams
section may be valuable as a reference when troubleshooting system circuitry. Specific troubleshooting
information is presented in the
Maintenance. Troubleshooting
section of this manual.
NOTE
Unless otherwise specified, the text, tables, and figures in this section refer to both
the 318/318S1 and the 338/338S1. Differences are called out as they occur.
DIGITAL LOGIC CONVENTIONS
Digital logic techniques are used to perform most functions within this instrument. Function and operation of the logic
circuits are represented by standard logic symbols and terms. All logic functions are described using the positive logic
convention. Positive logic is a system of notation whereby the more positive of two levels is the true, or 1 state; and the
more negative level is the false, or 0 state.
In logic descriptions, the more positive of the two logic voltages is referred to as high, and the more negative state as low.
The specific voltages that constitute a high or low state vary between different electronic devices.
Whenever a line name on a schematic is referred to within the text, that line name may be overscored, SIGNAL, indicating
that the line is an active low. Line names without overscores are active high.
To best understand the circuitry, cross-reference the descriptions in this section with the block diagrams in the
Diagrams
section. Refer to the Table of Contents at the front of this manual to locate individual circuit descriptions.
GENERAL SYSTEM DESCRIPTION
The following discussion provides an overall description of the 318/338 Logic Analyzer. Refer to the simplified block
diagrams in this section, and to the system block diagrams in the
Diagrams
section of this manual. Each major block in
these diagrams represents a major circuit within the instrument. The numbered diamond symbol on each block refers to
the associated schematic diagram for that circuit (also located in the
Diagrams
section).
The instrument can be divided into two sections:
• Acquisition Module
• Mainframe
4-1
Summary of Contents for 318
Page 119: ...318 VERIFICATION AND ADJUSTMENT PROCEDURES ...
Page 182: ...338 VERIFICATION AND ADJUSTMENT PROCEDURES ...
Page 253: ...318 ___________________ TROUBLESHOOTING TREES ...
Page 344: ...338 TROUBLESHOOTING TREES ...
Page 517: ...TM 11 6625 3145 14 318 338 4434 923 318 Block Diagram ...
Page 518: ...TM 11 6625 3145 14 318 338 4434 924 338 Block Diagram ...
Page 519: ...TM 11 6625 3145 14 318 338 4434 925 318 Acquisition Module Wiring Diagram ...
Page 520: ...TM 11 6625 3145 14 318 338 4434 926 318 338 Mainframe Wiring Diagram ...
Page 521: ...TM 11 6625 3145 14 318 338 4434 926 338 Acquisition Module Wiring Diagram ...
Page 522: ...TM 11 6625 3145 14 318 338 4434 928 Figure 9 1 318 A01 Input A Board Component Locations ...
Page 526: ...TM 11 6625 3145 14 ...
Page 528: ...TM 11 6625 3145 14 Figure 9 3 318 338 A03 ACQ Control Board Component Locations ...
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Page 542: ...TM 11 6625 3145 14 Figure 9 8 318 338 A10 CRT Board Component Locations ...
Page 544: ...TM 11 6625 3145 14 Figure 9 9 318 338 A11 Inverter Board component Locations ...
Page 546: ...TM 11 6625 3145 14 Figure 9 10 318 338 A12 Regulator Board Component Locations ...
Page 551: ...TM 11 6625 3145 14 Figure 9 12 338 A01 Input A Board Component Locations ...
Page 553: ...TM 11 6625 3145 14 318 338 SERVICE ...
Page 554: ......
Page 555: ...PIN 058584 ...