HP 1660E Series Service Manual page 209

Theory of Operation
The HP 1660E/ES/EP-Series Logic Analyzer
HP-IB Interface
The instrument interfaces to liP-IE as defined by IEEE Standard 488.2. The interface
consists of an liP-IE controller and two octal drivers/receivers. The microprocessor routes
liP-IE data to the controller. The controller then buffers the 8-bit HP-IE data bits and
generates the bus handshaking signals. The data and handshaking signals are then routed to
the liP-IE bus through the octal line drivers/receivers. The drivers/receivers provide data and
control signal transfer between the bus and controller.
RS-232-C Interface
The instrument RS-232-C interface is compatible with standard RS-232-C protocol. The
interface consists of a controller and drivers/receivers. The controller serializes parallel data
from the microprocessor for transmission. At the same time the controller also receives serial
data and converts the data to parallel data characters for the microprocessor.
The controller contains a baud rate generator that can be programmed from the logic analyzer
front panel for one of eight baud rates. Other RS-232-C communications parameters can also
be programmed from the logic analyzer front panel.
The drivers/receivers interface the instrument with data communications equipment. Slew
rate control is provided on the ICs eliminating the need for external capacitors.
LCD Display Assembly
The LCD dicplay is a Mitsubishi 8A-inch industrial-quality TFT active display. 6 bits of display
data from the CPU board result in a 640x480 VGA resolution at the display.
Flexible Disk Drive
The disk drive assembly is a high density disk drive that formats double-sided, double-density
or high density disks in LIF or DOS format. A disk drive controller on the CPU board controls
the disk drive. Signals are routed directly to the disk drive through the disk drive cable.
Power Supply
A low voltage power supply provides all DC voltages needed to operate the logic analyzer.
The power supply also provides the +5 Vdc voltage to the probe cables to power logic analyzer
accessories and analysis probes.
Unfiltered voltages of +12 V, -12 V, +5 V, -5.2 V, and +3.5 V are supplied to the acquisition
board where they are filtered and distributed to the CPU board, CRT Monitor Assembly, and
probe cables.
LAN Interface
The LAN interface is primarily a single LAN integrated circuit with supporting components.
Isolation circuitry for the LAN port is included on the
va
board. The LAN interface circuitry is
enabled only on the HP 1660EIES-series products with LAN option installed. The
1660EP-series comes standard with the LAN interface.
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