Keithley Instruments, Inc. warrants that, for a period of one (1) year from the date of shipment (3 years for Models 2000,
2001, 2002, 2010 and 2700), the Keithley Hardware product will be free from defects in materials or workmanship. This
warranty will be honored provided the defect has not been caused by use of the Keithley Hardware not in accordance with
the instructions for the product. This warranty shall be null and void upon: (1) any modification of Keithley Hardware that
is made by other than Keithley and not approved in writing by Keithley or (2) operation of the Keithley Hardware outside
of the environmental specifications therefore.
Upon receiving notification of a defect in the Keithley Hardware during the warranty period, Keithley will, at its option,
either repair or replace such Keithley Hardware. During the first ninety days of the warranty period, Keithley will, at its
option, supply the necessary on site labor to return the product to the condition prior to the notification of a defect. Failure
to notify Keithley of a defect during the warranty shall relieve Keithley of its obligations and liabilities under this
warranty.
Other Hardware
The portion of the product that is not manufactured by Keithley (Other Hardware) shall not be covered by this warranty,
and Keithley shall have no duty of obligation to enforce any manufacturers' warranties on behalf of the customer. On those
other manufacturers’ products that Keithley purchases for resale, Keithley shall have no duty of obligation to enforce any
manufacturers’ warranties on behalf of the customer.
Software
Keithley warrants that for a period of one (1) year from date of shipment, the Keithley produced portion of the software or
firmware (Keithley Software) will conform in all material respects with the published specifications provided such Keithley
Software is used on the product for which it is intended and otherwise in accordance with the instructions therefore.
Keithley does not warrant that operation of the Keithley Software will be uninterrupted or error-free and/or that the Keithley
Software will be adequate for the customer's intended application and/or use. This warranty shall be null and void upon any
modification of the Keithley Software that is made by other than Keithley and not approved in writing by Keithley.
If Keithley receives notification of a Keithley Software nonconformity that is covered by this warranty during the warranty
period, Keithley will review the conditions described in such notice. Such notice must state the published specification(s)
to which the Keithley Software fails to conform and the manner in which the Keithley Software fails to conform to such
published specification(s) with sufficient specificity to permit Keithley to correct such nonconformity. If Keithley determines that the Keithley Software does not conform with the published specifications, Keithley will, at its option, provide
either the programming services necessary to correct such nonconformity or develop a program change to bypass such
nonconformity in the Keithley Software. Failure to notify Keithley of a nonconformity during the warranty shall relieve
Keithley of its obligations and liabilities under this warranty.
Other Software
OEM software that is not produced by Keithley (Other Software) shall not be covered by this warranty, and Keithley shall
have no duty or obligation to enforce any OEM's warranties on behalf of the customer.
Other Items
Keithley warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes,
and documentation.
Items not Covered under Warranty
This warranty does not apply to fuses, non-rechargeable batteries, damage from battery leakage, or problems arising from
normal wear or failure to follow instructions.
Limitation of Warranty
This warranty does not apply to defects resulting from product modification made by Purchaser without Keithley's express
written consent, or by misuse of any product or part.
Disclaimer of Warranties
EXCEPT FOR THE EXPRESS WARRANTIES ABOVE KEITHLEY DISCLAIMS ALL OTHER WARRANTIES,
EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION, ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. KEITHLEY DISCLAIMS ALL WARRANTIES WITH
RESPECT TO THE OTHER HARDWARE AND OTHER SOFTWARE.
Limitation of Liability
KEITHLEY INSTRUMENTS SHALL IN NO EVENT, REGARDLESS OF CAUSE, ASSUME RESPONSIBILITY FOR
OR BE LIABLE FOR: (1) ECONOMICAL, INCIDENTAL, CONSEQUENTIAL, INDIRECT, SPECIAL, PUNITIVE OR
EXEMPLARY DAMAGES, WHETHER CLAIMED UNDER CONTRACT, TORT OR ANY OTHER LEGAL THEORY,
(2) LOSS OF OR DAMAGE TO THE CUSTOMER'S DATA OR PROGRAMMING, OR (3) PENALTIES OR PENALTY
CLAUSES OF ANY DESCRIPTION OR INDEMNIFICATION OF THE CUSTOMER OR OTHERS FOR COSTS, DAMAGES, OR EXPENSES RELATED TO THE GOODS OR SERVICES PROVIDED UNDER THIS WARRANTY.
The following safety precautions should be observed before using this product and any associated instrumentation.
Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations
where hazardous conditions may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety
precautions required to avoid possible injury. Read and follow all installation, operation, and maintenance information
carefully before using the product. Refer to the manual for complete product specifications.
If the product is used in a manner not specified, the protection provided by the product may be impaired.
The types of product users are:
Responsible body
the equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately
trained.
Operators
of the instrument. They must be protected from electric shock and contact with hazardous live circuits.
Maintenance personnel
the line voltage or replacing consumable materials. Maintenance procedures are described in the manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be performed only by service personnel.
Service personnel are trained to work on live circuits, and perform safe installations and repairs of products. Only
properly trained service personnel may perform installation and service procedures.
Keithley products are designed for use with electrical signals that are rated Installation Category I and Installation
Category II, as described in the International Electrotechnical Commission (IEC) Standard IEC 60664. Most measurement, control, and data I/O signals are Installation Category I and must not be directly connected to mains voltage
or to voltage sources with high transient over-voltages. Installation Category II connections require protection for high
transient over-voltages often associated with local AC mains connections. Assume all measurement, control, and data
I/O connections are for connection to Category I sources unless otherwise marked or described in the Manual.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or
test fixtures. The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels
greater than 30V RMS, 42.4V peak, or 60VDC are present.
age is present in any unknown circuit before measuring.
Operators of this product must be protected from electric shock at all times. The responsible body must ensure that
operators are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential human contact. Product operators in these circumstances must be trained to protect themselves from
the risk of electric shock. If the circuit is capable of operating at or above 1000 volts,
may be exposed.
Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance
limited sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards,
install protective devices to limit fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect
the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.
is the individual or group responsible for the use and maintenance of equipment, for ensuring that
use the product for its intended function. They must be trained in electrical safety procedures and proper use
perform routine procedures on the product to keep it operating properly, for example, setting
afety Precautions
A good safety practice is to expect that hazardous volt-
no conductive part of the circuit
5/02
When installing equipment where access to the main power cord is restricted, such as rack mounting, a separate main
input power disconnect device must be provided, in close proximity to the equipment and within easy reach of the
operator.
For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting
or disconnecting cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth)
ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the
voltage being measured.
The instrument and accessories must be used in accordance with its specifications and operating instructions or the
safety of the equipment may be impaired.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or switching card.
When fuses are used in a product, replace with same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground con-
nections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation re-
quires the use of a lid interlock.
If or is present, connect it to safety earth ground using the wire recommended in the user documentation.
!
The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.
The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined
effect of normal and common mode voltages. Use standard safety precautions to avoid personal contact with these
voltages.
The
WARNING
associated information very carefully before performing the indicated procedure.
The
CAUTION
the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits, including the power
transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable
national safety approvals, may be used if the rating and type are the same. Other components that are not safety related
may be purchased from other suppliers as long as they are equivalent to the original component. (Note that selected parts
should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product.) If you
are unsure about the applicability of a replacement component, call a Keithley Instruments office for information.
To clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do
not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist
of a circuit board with no case or chassis (e.g., data acquisition board for installation into a computer) should never
require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected,
the board should be returned to the factory for proper cleaning/servicing.
heading in a manual explains dangers that might result in personal injury or death. Always read the
heading in a manual explains hazards that could damage the instrument. Such damage may invalidate
The information contained in this manual is believed to be accurate and reliable. Ho we v er, the
manufacturer assumes no responsibility for its use; nor for any infringements of patents or
other rights of third parties that may result from its use. No license is granted by implication or
otherwise under any patent rights of the manufacturer.
THE MANUFACTURER SHALL NOT BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES RELATED TO THE USE OF THIS PRODUCT. THIS
PRODUCT IS NOT DESIGNED WITH COMPONENTS OF A LEVEL OF RELIABILITY
THAT IS SUITED FOR USE IN LIFE SUPPORT OR CRITICAL APPLICATIONS.
DriverLINX, SSTNET, and LabOBJX are registered trademarks and DriverLINX/VB is a
trademark of Scientific Software Tools, Inc.
Microsoft and Windows are registered trademarks and Visual C++ and Visual Basic are trademarks of Microsoft Corporation.
Borland is a registered trademark and Borland C++, Delphi, and Turbo Pascal are trademarks
of Borland International, Inc.
IBM is a registered trademark of International Business Machines Corporation.
Acrobat is a registered trademark of Adobe Systems Incorporated.
All other brand and product names are trademarks or registered trademarks of their respective
This guide is for persons needing to understand the installation, interface
requirements, functions, and operation of the DAS-1201 and DAS-1202
boards. This manual uses the term DAS-1200 Series boards to refer to
both boards.
To follow the information and instructions contained in this manual, you
must be familiar with the operation of an IBM PC or compatible in the
Windows 95/98 or Windows NT environment. You must also be familiar
with data acquisition principles and their applications.
ix
Manual Organization
Table 1 lists the topics that this guide focuses on and indicates where you
can find information about a topic.
Table 1. Finding Information
To learn more about:See:
The capabilities of DAS-1200 Series boardsChapter 1
What software is available for the boardsChapter 1
What accessories are available for the boardsChapter 1
Functionality of DAS-1200 Series boardsChapter 2
Setting up DAS-1200 Series board switch-configurable optionsChapter 3
Installing DriverLINX softwareChapter 3
Installing the DAS-1200 Series boardsChapter 3
Configuring the DAS-1200 Series board using DriverLINXChapter 3
Attaching accessoriesChapter 4
Precautions to observe when connecting signalsChapter 4
Using the DriverLINX Control Panel for test and data acquisitionChapter 5
Calibrating the boardChapter 6
Troubleshooting and obtaining technical supportChapter 7
DAS-1200 Series specificationsAppendix A
I/O connector pin assignmentsAppendix B
The register-level I/O mapAppendix C
x
Related Documents
You can find more information on DAS-1200 Series software and
accessories in the related documents listed in Table 2.
DriverLINX Installation and Configuration Guide
DriverLINX Appendix F: Configuration and Implementation. Notes for
Keithley DAS-16/1600
boards).
DriverLINX Analog I/O Programming Guide
DriverLINX Digital I/O Programming Guide
DriverLINX Counter/Timer Programming Guide
EXP-16 & EXP-16A Expansion Multiplexer/Amplifier System User’s
Guide
Table 2. Related Documents
Document
(this manaul also includes DAS-1200 Series
EXP-GP Signal Conditioning Multiplexer User’s Guide
MB Series User’s Guide
SSH-4/A Simultaneous Sample & Hold Module User’s Guide
SSH-8 User’s Guide
ISO-4 User’s Guide
xi
1
Overview
The DAS-1200 Series is a family of high-performance analog and digital
I/O boards with DriverLINX software that requires:
●
an IBM PC or compatible AT (386 or Pentium CPU) with minimum
of 2 MB of memory
at least one floppy disk drive and one fixed disk drive
●
Microsoft Windows 95/98, or Windows NT 4.0 or higher
●
●
a compiler supporting Microsoft Windows development
●
a mouse is highly recommended.
This section describes the features of the DAS-1200 Series boards, the
software that supports them, and available accessories.
Features
The DAS-1200 Series features are as follows:
●
Boards are switch-configurable for 16 single-ended or eight
differential analog input channels.
Analog inputs are bipolar with a maximum range of ±5 V.
●
The gain applied to analog input channels is switch-configurable. The
●
DAS-1201 has switch-configurable gains of 1, 10, 100, and 500. The
DAS-1202 has switch-configurable gains of 1, 2, 4, and 8.
1-1
Analog inputs are sampled with 12-bit resolution at a maximum of
●
50 ksamples/s for the DAS-1201 and 100 ksamples/s for the
DAS-1202.
●
The base I/O address and Direct Memory Address (DMA) channel
are switch-configurable; interrupt levels are software-configurable.
Analog-to-digital (A/D) conversions can be started through an y of the
●
following methods:
–software command
–onboard pacer clock
–external pacer clock
●
External Simultaneous Sample-and-Hold (SSH) hardware is
supported.
Data transfers can be performed by any of the following methods:
●
–program control
–interrupt service routines
–DMA transfer
The boards perform 8-bit data transfers on the ISA bus.
●
●
A 3-channel programmable counter/timer (82C54) provides timing
for analog input operations or generation of output pulses at any rate
from 1 pulse/hour to 100 kHz. The 82C54 counter/timer can also be
used to measure frequency, period, and pulse width.
1-2Overview
The DAS-1200 Series boards provide a total of 32 bits of digital I/O.
●
Four unidirectional digital inputs and four unidirectional digital
outputs are provided on the main I/O connector; 24 bits of
bidirectional digital I/O are provided on the PIO cable connector (J4).
These 24 bits are configured as two 8-bit ports and two 4-bit ports
that can be set independently for input or output.
The 24-bits of bidirectional digital I/O are compatible with the
Keithley PIO-12 board. You can use these ports to gate the
counter/timer, control multiplexers, and read the status of external
devices.
●
The boards are backward compatible with the DAS-16 and DAS-16F
boards. Programs for the DAS-16 and DAS-16F run on the
DAS-1200 Series without modification.
For more information on these features, refer to the functional description
in Section 2.
Supporting Software
This section describes how to install the DAS-1200 Series standard
software package and supporting software packages. The contents of
these software packages are described as follows:
DAS-1200 Series standard software package
●
— Shipped with
DAS-1200 Series boards. Includes DriverLINX for Microsoft
Windows 95/98 or Windows NT and function libraries for writing
application programs under W indows in a high-le vel language such as
Microsoft Visual C++, Microsoft Visual Basic, Borland Delphi
support files, LabVIEW, utility programs, and language-specific
example programs.
●
DriverLINX —
the high-performance real-time data-acquisition
device drivers for Windows application development includes:
DriverLINX API DLLs
●
and drivers supporting the DAS-1200
Series hardware.
1-3
Analog I/O Panel —
●
A DriverLINX program that verifies the
installation and configuration of DriverLINX to your DAS-1200
Series board and demonstrates several virtual bench-top
instruments.
●
Learn DriverLINX —
an interactive learning and demonstration
program for DriverLINX that includes a Digital Storage
Oscilloscope.
on DriverLINX installation and
configuration, analog and digital I/O programming, counter/timer
programming; technical reference, and information specific to the
DAS-1200 Series hardware.
●
DAS-1200 Series utilities —
The following utilities are provided as
part of the DAS-1200 Series standard software package:
●
Analog I/O
Utility —
DriverLINX utility used for data acquisition
and testing board operation.
●
Test Utility —
DriverLINX utility used for testing board
operation.
for the
●
Calibration Utility —
DriverLINX utility used for calibration.
1-4Overview
Accessories
The following accessories are av ailable for use with the DAS-1200 Series
boards.
●
STA-16 — Screw terminal adapter accessory. You can use this
accessory to connect signals from the main I/O connector (J1) to
screw terminals.
●
STA-U —
Universal screw terminal accessory. You can use this
accessory to connect interface signals from the PIO cable connector
(J4) to screw terminals.
Screw terminal panel with a 37-pin D-type connector.
4-channel isolated expansion multiplexer.
4-channel simultaneous sample-and-hold accessory.
Plug-in, isolated,
signal-conditioning modules and the backplanes that hold them.
EXP-16 and EXP-16/A —
●
16-channel expansion multiplexer and
signal conditioning accessory; requires the S-1600 cable and the
PG-408A option.
●
EXP-GP —
8-channel signal conditioning accessory with
Wheatstone bridge and RTD interface; requires the S-1600 cable.
1-5
2
Functional Description
This section describes the following features of D AS-1200 Series boards:
●
Analog input features
●
Digital I/O features
●
82C54 counter/timer features
Wait state selection
●
●
Power
Together with the DAS-1200 Series block diagram shown in Figure 2-1,
these descriptions are offered to familiarize you with the operating
options and to enable you to make the best use of your board.
2-1
Ch 0/0
Ch 7/15
8 or 16
Analog
Input
Channels
Diff./S.E.
Selection
Instrumentation
Gain Select
Switch
Data
Buffers
Amplifier
Mux Increment
& Control Logic
Internal Data Bus
Control
Register
Address Decode
& Select
Sampling
12-bit ADC
ADC & Mux
Data Register
Status
Register
Clock
Select
Logic
Timer
Enable
Register
Control Logic
DMA
Level Select
DMA
Port A
Port B
Port Cl
Port Ch
Output
Register
Register
100 kHz
Interrupt Control
Logic
4-bit
4-bit
Input
16-bit
Counter
16-bit
Counter
16-bit
Counter
1 MHz
8 Bits
8 Bits
4 Bits
4 Bits
OP3
OP2
OP1
OP0
IP3
IP2/CNTR 0 Gate
IP1/XTRIG
IP0/TRIG
XPCLK0/
CNTR 0
Out
Programmable
Interval Timer
CNTR 2
Out
CNTR 0
CLK In
10 MHz
ISA PC AT, PC/XT BUS
.
Figure 2-1. Functional Block Diagram
2-2Functional Description
Analog Input Features
The analog input section of a DAS-1200 Series board multiplexes all the
active input channels (up to 16 single-ended or eight dif ferential) do wn to
a single, 12-bit sampling analog-to-digital converter (ADC).
DAS-1200 Series boards operate in bipolar input mode only. Bipolar
signals can swing up and down between negative and positive peak
values. The DAS-1200 Series boards have a maximum range of
+5 V and use left-justified, offset binary to represent signals.
Other features of this section include input configurations, gain selection,
conversion modes, triggers, clock sources, and data transfer modes. These
features are described in the following sections.
Differential/Single-Ended Selection
Using configuration switches, you can select either eight differential or 16
single-ended inputs. Differential inputs measure the difference between
two signals. Single-ended inputs are referred to a common ground.
-
5 V to
Generally , you want to use differential inputs for low-level signals whose
noise component is a significant part of the signal or for signals that have
non-ground common mode. You want to use single-ended inputs for
high-level signals whose noise component is not significant.
The specific level at which input configurations work best is dependent
upon the application. However, you generally use differential inputs for
voltage ranges of 100 mV and less.
Channel Selection in Expanded Configurations
As previously mentioned, the D AS-1200 Series supports 16 single-ended
or eight differential analog input channels. If you require additional
analog input channels or signal conditioning for transducer inputs, you
can use any combination of up to eight 16-channel EXP-16 or EXP-16/A
expansion accessories, and/or eight 8-channel EXP-GP expansion
accessories to increase the number of available channels to 128.
2-3
When you daisy-chain expansion accessories from the analog inputs, it is
recommended that the first expansion accessory multiplex onboard use
channel 0, the next expansion accessory multiplex channel 1, and so on.
Selection of an onboard channel is made via jumper settings on the
expansion accessory.
You can access any unused onboard channels by including an STA-16
screw terminal accessory in the daisy-chain configuration. Figure 2-2
illustrates how expansion boards and accessories interface with the analog
channels of DAS-1200 Series boards.
DAS-1200
Series Boards
ch 0
ch 1
ch 2
Transducer
16 multiplexed
input channels
8 multiplexed
input channels
.
.
ch 7
digital output
port
Expansion Channel
Select Lines (OP0 to 3)
Figure 2-2. Expanding the Analog Inputs of DAS-1200 Series Boards
You can also use up to four MB02 backplanes to increase the number of
available channels to 64 isolated or 12 non-isolated. For more information
about connecting channel expansion boards, refer to Section 4.
EXP-16 orEXP-GPSTA-16
EXP-16/A
2-4Functional Description
Gain Selection
Notes:
You must specify a single-ended input configuration for all
onboard channels associated with channels on MB02 backplanes.
If you are using EXP-16, EXP-16/A, or EXP-GP expansion accessories
or MB Series backplanes, the digital output lines of the DAS-1200 Series
board select a particular channel on the expansion accessory or backplane
to read.
The switch-configurable gain that you select is applied to an incoming
signal as a multiplication factor; gain allows you to amplify a signal to a
range that the ADC can accurately measure.
For example, if the ADC handles signals in the ±5 V range and you want
to measure a signal in the range of ±0.5 V, you would use a gain of 10 to
amplify the signal to the ±5 V range. Similarly, if you wanted to measure
a signal that was already in the ±5 V range, you would select a gain of 1.
The available gains, their corresponding input ranges, and throughput
rates are listed in Table 2-1 for the DAS-1201 and Table 2-2 for the
DAS-1202.
Table 2-1. DAS-1201 Gains, Ranges, and Throughput Rates
Table 2-2. DAS-1202 Gains, Ranges, and Throughput Rates
Conversion Modes
DAS-1200 Series boards support the following conversion modes:
●
Paced mode
is the mode best-suited for continuous scanning of multiple channels
at a constant rate. In paced mode, the conversion rate equals the pacer
clock rate. The sample rate, which is the rate at which a single
channel is sampled, is the pacer clock rate divided by the number of
channels being sampled.
— Paced mode is the default data conversion mode and
Burst mode
●
— In burst mode, each pulse from the pacer clock begins
a scan of one to sixteen channels. The conversion rate during a burst
mode scan is equal to the rate of the burst mode conversion clock.
The sample rate, which is the rate at which a single channel is
sampled, is equal to the pacer clock rate.
DAS-1200 Series software allows you to program the pacer clock to
adjust the interval between burst mode scans. This software also
allows you to adjust the burst mode conversion rate. The burst mode
conversion clock frequency is programmable for a range of 3.94 kHz
to 100 kHz.
Burst mode can also be used for pseudo-simultaneous
sample-and-hold in conjunction with DMA or interrupt operations.
2-6Functional Description
The sample rate (pacer clock rate) should be set for no more than the
burst mode conversion clock rate divided by the number of channels
in the burst. The maximum burst mode conversion clock rate is
gain-sensitive, as shown in Table 2-1 and Table 2-2.
Figure 2-3 shows the timing relationships of the paced and burst modes
for analog input channel 4 to channel 7.
Figure 2-3. Timing Relationships of Conversion Modes
ch4
ch4
ch5 ch6 ch7ch4 ch5 ch6 ch7
ch5
Clock Sources
The following clock sources are available for conversions on DAS-1200
Series boards:
●
Software
— DAS-1200 Series boards allow you to acquire single or
multiple samples under program control.
●
Hardware (internal clock source)
— The internal pacer clock is
derived from the onboard 82C54 counter/timer and a
switch-configurable, crystal-controlled 1 MHz or 10 MHz timebase.
The pacer clock uses two cascaded counters of the 82C54. The
maximum allowable rate is 100 ksamples/s (for the DAS-1202) or
50 ksamples/s (for the DAS-1201).
2-7
The minimum conversions per hour is determined as follows:
10MHz
------------------2 .328 103–¥8.38==
32
2
1MHz
---------------2 .328 104–¥0.838==
32
2
When not used to pace the analog input, the internal clock source can
pace other events, such as digital I/O, through the use of interrupts.
●
Hardware (external clock source)
— The external pacer clock
source must be an externally applied, TTL-compatible, rising-edge
signal attached to the IP0/TRIG 0/XPCLK pin (25) of the main I/O
connector (J1).
An external clock source is useful if you want to pace at rates not
available with the 82C54 counter/timer, if you want to pace at uneven
intervals, or if you want to pace on the basis of an external event. An
external clock also allows you to synchronize multiple boards with a
common timing source.
Notes:
The ADC on the DAS-1202 acquires samples at a maximum of
100 ksamples/s (one sample every 10.0 µs); the ADC on the DAS-1201
acquires samples at a maximum of 50 ksamples/s (one sample every
20.0 µs). If you are using an external clock, make sure that it does not
initiate conversions at a faster rate than the ADC can handle.
If you are acquiring samples from multiple channels, the maximum
sampling rate for each channel is equal to 100 ksamples/s divided by the
number of channels (for the DAS-1202) or 50 ksamples/s divided by the
number of channels (for the DAS-1201).
Triggers
A trigger starts an analog input operation. The polarity of external triggers
in the DAS-1200 Series boards is software-configurable. You can use one
of the following trigger sources to start an analog input operation:
●
Internal
begin immediately.
2-8Functional Description
— When you enable the analog input operation, con versions
External Analog
●
— While an analog trigger is not a hardware feature
of the DAS-1200 Series boards, you can program an analog trigger
using one of the analog input channels as the trigger channel.
DriverLINX provides functions for an analog trigger; refer to the
DriverLINX Appendix F: Configuration and Implementation. Notes
for Keithley DAS-16/1600
(this manual also includes DAS-1200
Series boards).
External Digital
●
— While a digital trigger is not a hardware feature
of the DAS-1200 Series boards, you can program a digital trigger
using one of the digital input channels as the trigger channel.
DriverLINX provides functions for an analog trigger; refer to the
DriverLINX Appendix F: Configuration and Implementation. Notes
for Keithley DAS-16/1600
(this manual also includes DAS-1200
Series boards).
Connect the digital trigger to the digital input IP1/XTRIG pin (6) of
the main I/O connector (J1). Trigger types are as follows:
–
Positive-edge trigger
- Conversions begin on the rising edge of
the trigger signal.
–
Negative-edge trigger
- Conversions begin on the falling edge of
the trigger signal.
–
Positive-level trigger
- Conversions begin when the signal is
above a positive level.
–
Negative-level trigger
- Conversions begin when the signal is
below a negative level.
Data T ransfer Modes
You can transfer data from the DAS-1200 Series boards to the computer
using the following data transfer modes:
●
Single mode
acquires a single sample from a single channel; you cannot perform
any other operation until the single-mode operation is complete.
— In single-mode operation, a data acquisition board
2-9
Synchronous
●
— In synchronous-mode operation, a data acquisition
board acquires one or more samples from one or more channels; you
cannot perform any other operation until the synchronous-mode
operation is complete.
●
Interrupt
— You can program the board to acquire data, then
generate an interrupt when data is available for transfer. When
interrupt mode is used, data is transferred by an interrupt service
routine; you can perform other operations while an interrupt mode
operation is in progress. The interrupt level is software-configurable.
Unpredictable interrupt latencies in the W indows environment tend to
make maximum board speeds unachievable in the interrupt mode.
When in the Windows environment, you are advised to use DMA
mode instead of interrupt mode.
●
DMA
— DMA is a method of bypassing the CPU to transfer data
directly between an I/O device and computer memory . In the IBM PC
family, DMA is directed by the DMA controller and executes
independently while the CPU is executing other instructions.
Therefore, you can perform other operations while a DMA mode
operation is in progress. The ability to run independently of the CPU
and at high-transfer rates makes DMA an attractive method for
transferring data in data acquisition systems.
DAS-1200 Series boards can use either DMA channel 1 or 3 to
perform single-cycle DMA transfers of A/D data from the board to
memory.
Generally, if you are programming an operation in the Windows
Enhanced Mode, you should use DMA to acquire data reliably at
maximum board speeds.
Digital I/O Features
DAS-1200 Series boards contain 32 bits of digital I/O.
Four unidirectional digital inputs (IP0 to IP3) and four unidirectional
digital outputs (OP0 to OP3) are accessible through the main I/O
connector (J1).
2-10Functional Description
24 bits of bidirectional digital I/O are available on the PIO cable
connector (J4). These 24 bits are configured as two 8-bit ports (A and B)
and two 4-bit ports (CL and CH) that you can set independently for input
or output.
Logic 1 on an I/O line indicates that the input/output is high; logic 0 on an
I/O line indicates that the input/output is low (see Table A-2 on page A-3
for logic levels). The digital inputs are compatible with TTL-le vel signals.
These inputs are provided with 10 kΩ pull-up resistors to +5 V; therefore,
the inputs appear high (logic 1) with no signal connected.
You can use the digital inputs and outputs for any general-purpose task
except the following:
If you are using an external digital trigger or gate, you must use
●
digital input line IP1/XTRIG to attach the trigger and digital input
line IP2/CTR 0/GATE to attach the counter 0 gate signal. In either of
these cases, you cannot use the corresponding bit for general-purpose
digital input.
●
If you are using an external pacer clock, you must use digital input
line IP0/TRIG 0/XPCLK to attach the external pacer clock signal; in
this case, you cannot use IP0/TRIG 0/XPCLK for general-purpose
digital input.
When the analog inputs are disabled, you can pace the digital I/O with
interrupts generated by the onboard pacer clock.
You can read and write a single value from and to a DAS-1200 Series
board using synchronous mode or single mode. You can read and write
multiple values from and to a DAS-1200 Series board using synchronous
mode or interrupt mode.
Counter/Timer Features
The DAS-1200 Series includes an 82C54 with three programmable
counters. Counters 1 and 2 are permanently cascaded and are used as the
internal A/D pacer clock.
2-11
Counter 0 is not used by the board, but can be used for functions such as
waveform generation, measuring frequency and period, and generating
time delays. You access counter 0 functions through the board’s I/O
registers or through the Function Call Driver.
Note:
functions with Function Call Driver programming can produce
unexpected results because the Function Call Driver relies on structures it
sets up.
You can use software to select IP0/TRIG 0/XPCLK (pin 25) of the main
I/O connector for use as a hardware gate. The gate provides a means of
holding off clock pulses (from counters 1 and 2) to the ADC until
IP0/TRIG 0/XPCLK goes high.
Attempts to combine register-level programming of counter/timer
Wait State Selection
Although most current-generation PCs and compatibles extend bus cycles
during 8-bit data transfers, the DAS-1200 Series provides a
switch-configurable option that allows you to enable or disable wait states
that extend bus cycles during 8-bit data transfers.
Inclusion of this option also maintains backward compatibility with
DAS-16 and D AS-16F Series boards that may be used in early generation
machines.
Power
+5 V power is available from the main I/O connector (J1). The +5 V
supply is brought out from your host computer.
2-12Functional Description
3
Setup and I
This section describes inspection, software installation, configuration,
and hardware installation for DAS-1200 Series boards.
Read this chapter and all related DriverLINX documentation before you
attempt to install and use your DAS-1200 Series board.
Inspecting Y our Package
Caution:
damage certain electrical components on any circuit board. Before
handling any board, discharge static electricity from yourself by touching
a grounded conductor such as your computer chassis (your computer
must be turned off). Whenever you handle a board, hold it by the edges
and avoid touching any board components, cable connectors, or
gold-plated edge connectors.
A discharge of static electricity from your hands can seriously
nstallation
Use the following procedure to unwrap and inspect a DAS-1200 Series
board:
1. Factory packaging of the DAS-1200 Series board includes a final
wrap of protective, anti-static material. Remove the board from its
anti-static wrapping material. You may store the wrapping material
for possible future use.
2. Inspect the board for signs of damage. If damage is apparent, arrange
to return the board to the factory (see “Technical Support” on page
7-6).
3-1
3. Check the remaining contents of your package against the packing
list to be sure your order is complete. Report any missing items
immediately.
4. When you are satisfied with the inspection, proceed with the software
and hardware setup instructions.
Note:
further adjustment prior to installation. If at a later time you decide to
recalibrate the board, refer to Section 6 for instructions.
Data acquisition products are factory calibrated; they require no
Setting Switch-Configurable Options
This section contains information and illustrations that you can use to
verify default switch configurations and reconfigure switch-configurable
options. Sections 1 and 2 contain information about product features that
help you determine the board configuration that best suits the needs of
your application.
Figure 3-1 shows the switches for DAS-1200 Series boards. The
remaining sections describe the switches and how to configure them.
3-2Setup and Installation
Gain Selection Switch
TP 2
Note that a switch
in the ON position
outputs a logic 0
J4
WAIT (W): UP = OFF DN = ON
CLOCK (C): UP = 1 MHz DN = 10 MHz
BASE ADDRESSC (clock select)
987654
12345678
o
n
W (wait state enable)
S3
Figure 3-1. Default Switch Configuration for DAS-1200 Series Boards
Setting the Gain Selection Switch
Switch S2 on the DAS-1200 Series board is a 3-position switch that
selects the gain that you want applied to all of your analog input channels.
TP 1
R2
R3
13
DMA SEL
CHAN
S1
S4
S2
16 8
J1
Note:
Switch S2 is a direct input to the instrumentation amplifier. You do
not have to reset or power-up the board to apply the change in gain to
analog input channels.
3-3
Figure 3-2 shows the 3-position gain selection switch that is set up
through the rear mounting flange.
rear view of gain
selection switch S2
1 2 3
ON
Main I/O Connector (J1)
Figure 3-2. Gain Selection Switch as Viewed Through Mounting Flange
Table 3-1 lists the switch positions for each of the gains available.
Table 3-1. Gain Selection Switch Positions
GAINSwitch Position
DAS-1201 DAS-1202 123
11OFF OFF OFF
102ONOFF OFF
1004OFF ONOFF
5008OFF OFF ON
3-4Setup and Installation
Setting the Chan 8/16 Switch
Switch S1 on the DAS-1200 Series board is a 2-position switch that
configures the A/D inputs as eight differential or 16 single-ended inputs.
The default setting is eight differential inputs.
Setting an Alternate Base Address
Switch S3 on the DAS-1200 Series is a single, 8-position DIP switch that
accommodates the base address, the clock select, and the wait state enable
parameters. The default base address setting is 300h (768 decimal).
Figure 3-3 shows the default switch positions for the base address, clock
select, and wait state enable switches.
Address
A41016
A52032
A64064
A780128
A8100256
A9200512
Hex
Value Line
Decimal
Value
12345678
o
n
CLK SEL
WAITEN
On = 1 MHz
Off = 10 MHz
On = No
Off = Yes
Note that a switch in the ON
position outputs a logic 0.
Figure 3-3. Base Address, Clock Select, and Wait State Enable Switch
987654
BASE ADDRESS
CW
The base address is read from the 8-position DIP switch located as shown
in Figure 3-1 for a DAS-1200 Series board. The base address switch is
preset at the factory for a hexadecimal value of 300h (768 decimal). If this
address conflicts with the address of another device in the computer
(including another DAS-1600/1400/1200 Series board), you must
reconfigure the base address switch.
3-5
To reconfigure this switch for another address, perform the following
steps:
1. Select an alternate address that does not conflict with another
installed device. See Table 3-2.
2. Use the configuration utility to create a new configuration file and
view the corresponding switch settings in the menu-box diagram.
3. Set up the base address switch to match the settings in the menu-box
diagram.
Note:
shown by the switch diagram in the menu box of the configuration utility.
The settings for the base-address switch must match the settings
Setting the Clock Select Switch
Position number 7 of the base address switch (see Figure 3-3) selects
either a 1 MHz or 10 MHz clock for the internal pacer clock. The default
is 10 MHz (Off).
Setting the Wait State Enable Switch
Position number 8 of the base address switch (see Figure 3-3) enables
wait states. The default setting is NO (On). If you experience intermittent
errors, you may correct the problem by setting this option to YES (Off).
Setting the DMA Channel Select Switch
Switch S4 on the DAS-1200 Series is a 2-position slide switch that selects
DMA channel 1 or 3. The default setting is 3.
3-6Setup and Installation
Installing and Configuring DriverLINX for DAS-1200
Series Boards
Caution:
and test any new hardware, you should e xit all other programs and, if you
use a disk cache, disable write caching. If the system does crash and
you’re using disk compression software or a disk cache utility, as a
precaution after any crash, run the utility that checks the directory
structures.
As a precaution against a system crash the first time you install
Installing the DAS-1200 Series Standard Software Package
Important:
DAS-1200, read the
and the
Series (this manual contains DAS-1200 information)
packaged with the DriverLINX software. They are accessed from the
DriverLINX CD-ROM after you have installed Adobe Acrobat.
Before Installing DriverLINX
1. Inventory your DAS-1200 board’s configuration settings.
Before you begin installing any hardware or software for the
DriverLINX Installation and Configuration Guide
Using DriverLINX with your Hardware — Keithley DAS-16/1600
manuals that are
2. Determine the resources your DAS-1200 Series board requires.
3. Inventory your computer’s resources already allocated to other
installed devices.
4. Determine whether your computer has sufficient resources for your
DAS-1200 board.
5. Determine whether your DAS-1200 board can use your computer’s
free resources.
6. Set any jumpers/switches to configure your DAS-1200 board to use
your computer’s free resources.
3-7
7. Set any other jumpers/switches to configure your DAS-1200 board
the way you want it to operate. Make a note of the switch and jumper
settings in order to configure the board using DriverLINX.
8. Install your DAS-1200 board into an appropriate free slot in your
computer.
Selecting the DriverLINX components to Install
For your convenience in installing and uninstalling just the DriverLINX
components you need, the DriverLINX CD Browser will assist you in
selecting the components to install:
●
Install Drivers
need for configuring your hardware and running third–party
data–acquisition applications that require DriverLINX.
●
Install Interfaces
example programs that you will need to develop custom applications
for DriverLINX using C/C++, Visual Basic, and Delphi.
●
Install LabVIEW Interface
example programs that you will need to develop applications for
DriverLINX using LabVIEW.
— This required component installs only the files you
— This optional component installs the files and
— This component installs the files and
Install Documentation
●
— This optional component installs
electronic documentation for DriverLINX that you can read, search,
and print using the Adobe Acrobat Reader.
●
Install Acrobat
— This optional component installs the Adobe
Acrobat Reader for the DriverLINX electronic documentation.
Installing DriverLINX
1. Insert the DriverLINX CD-ROM into your computer’s CD-ROM
Drive.
2. Start the DriverLINX setup program. On most systems, wait a few
seconds for automatic startup. Otherwise, run the setup.exe program
from the CD-ROM.
3-8Setup and Installation
3. The DriverLINX CD-ROM Browser Map window appears on the
screen. Click ‘Install Drivers,’ and follow the series of on–screen
instructions.
Note:
T o display an explanation of a menu option on the Dri v erLINX CD
browser map that appears next and on subsequent setup screens, place the
mouse pointer over the menu item. A star next to a menu item means that
the item was selected previously.
4. Select ‘Read Me First,’ and follow the instructions.
5. Select ‘Install Documentation.’ If you do not have Adobe Acrobat
installed on your computer, install it by selecting ‘Install Adobe
Acrobat.’
6. Open the manuals appropriate to the DAS-1200 installation and read
them before installing your DAS-1200 board or configuring
DriverLINX:
Installation and Configuration
●
●
Appendix F: Configuration and Implementation Notes—for
Keithley DAS-16/1600 (manual used for DAS-1200 Series
installation information)
DriverLINX Technical Reference Manual
●
●
DriverLINX Analog I/O Programming Guide
●
DriverLINX Digital I/O Programming Guide
DriverLINX Counter/Timer Programming Guide
●
Appendix, I/O Port, Interrupt, and DMA Channel Usage
●
●
Other manuals appropriate to your installation.
7. Following the DriverLINX prompts, turn off your computer and
install your DAS-1200 board into an appropriate free slot in your
computer.
3-9
Installing the Board
Caution:
your computer.
After reviewing your computer manufacturer’s documentation for
accessing computer internals, use the following steps to install a
DAS-1200 Series board in an accessory slot of your computer:
1. Turn off power to the computer and all attached equipment.
2. Remove the computer chassis cover.
3. Select an unoccupied accessory slot, and remove the corresponding
4. If your application uses the 24-bit digital I/O, remove the blank plate
Installing or removing a board while power is on can damage
Note:
You must observe the current-capacity limits of the PC supply;
allow for the power used by any other boards that may be in use. See
Table A-5 for DAS-1200 Series power requirements.
blank plate and retaining screws from the I/O connector panel. Save
the retaining screws for re-use in later steps.
and retaining screws of the adjacent slot. Save the retaining screws
for re-use in later steps.
5. Insert the board in the selected slot and secure the main I/O connector
mounting flange with the retaining screws.
6. When using the 24-bit digital I/O, connect the board end of the PIO
cable to the PIO cable connector (J4) on the DAS-1200 Series board.
When connecting the cable, align the raised arrow of the PIO cable
with the arrow imprinted on the PIO cable connector (J4). Secure the
mounting flange on the PIO cable to the connector panel next to the
main I/O connector (J1) with the retaining screws.
3-10Setup and Installation
7. Replace the computer cover.
8. Turn on power to the computer.
You can use the DriverLINX Control Panel (see Section 5) to verify board
operation.
Configuring the DAS-1200 Board with DriverLINX
Note:
Be sure to note and follow all programming differences between
installations for Windows NT and Windows 95/98.
Be sure to make note of the configuration of all switches and jumpers on
the board. You will use this information to enter the correct configuration
parameters using DriverLINX. Also locate an y information or notes about
the interrupt and DMA channels used by the other hardware devices in
your computer system.
Table 3-2 lists I/O addresses commonly used by IBM PC/XT, AT, and
compatible computers. Determine an even boundary of eight I/O
addresses within the range of 000H to 3F8H that is not being used by
another resource in your system (including another DAS-1200 Series
board), and set the switches to the appropriate base address.
Table 3-2. I/O Address Map (000H to 3FFH)
Address RangeUse
000H to 00FH8237 DMA #1
020H to 021H8259 PIC #1
040H to 043H8253 timer
060H to 063H8255 PPI (XT)
060H to 064H8742 controller (AT)
060H to 06FH8042 Keyboard controller
070H to 071HCMOS RAM and NMI mask register (AT)
080H to 08FHDMA page registers
3-11
Table 3-2. I/O Address Map (000H to 3FFH) (cont.)
Address RangeUse
0A0H to 0A1H8259 PIC #2 (AT)
0A0H to 0AFHNMI mask register (XT)
0C0H to 0DFH8237 DMA #2 (AT - word-mapped)
0F0H to 0FFH80287 numeric processor (AT)
170H to 177HHard disk controller #1
1F0H to 1F8HHard disk controller #2
1F0H to 1FFHHard disk controller (AT)
200H to 2FFHGame / control
210H to 21FHExpansion unit (XT)
238H to 23BHBus mouse
23CH to 23FHAlternate bus mouse
278H to 27FHParallel printer
2B0H to 2DFHEGA
2E0H to 2EFHGPIB (AT)
2E8H to 2EFHSerial port
2F8H to 2FFHSerial port
300H to 31FHPrototype card
320H to 32FHHard disk (XT)
370H to 377HFloppy disk controller #2
378H to 37FHParallel printer
380H to 38FHSDLC
3A0H to 3AFHSDLC
3B0H to 3BBHMDA
3BCH to 3BFHParallel printer
3C0H to 3CFHVGA EGA
3D0H to 3DFHCGA
3E8H to 3EFHSerial port
3F0H to 3F7HFloppy disk controller #1
3F8H to 3FFHSerial port
3-12Setup and Installation
The Expansion Board Configuration for Keithley D AS-1200 Series dialog
in DriverLINX allows you to record the settings of your analog input
multiplexers and enable the expansion channels. Make sure that the
switch settings match the settings you define in DriverLINX. Refer to the
DriverLINX Appendix F: Configuration and Implementation
Notes—Keithley DAS-16/1600 manual.
After you have successfully installed the DAS-1200 Series board in your
computer, start Windows.
Run “Learn DriverLINX”
(LearnDL.exe)
from the DriverLINX program
group to tell DriverLINX how you configured your DAS-1200 Series
board and to verify that everything is properly installed and configured.
1. Start Windows as you normally would and select the Program
Manager window. Install DriverLINX if you have not previously
done so.
2. Either select the “Learn DriverLINX” icon created when you
installed DriverLINX or enter “<drive>:/DRVLNX/LEARNDL” in
the
Command Line
by selecting the
edit box. The Command Line edit box is activ ated
Run...
option. <drive> is the letter of the hard disk
drive where DriverLINX is installed.
3. Immediately after loading Learn DL, the Open DriverLINX DLL
dialog box appears. Select the name of the hardware–specific DLL
from the list for your DAS-1200 Series board. The name is an
abbreviation of the board’s model number.
4. From the main menu bar of Learn DL, select the
choose
Select...
.
Device
menu and
5. Select the Logical Device you wish to configure and then click on the
OK
button (return).
6. Again select the
Device
menu and then choose the
to display the Device Configuration Dialog Box.
7. From the
Model
list, select the model name for your DAS-1200
Series board you are configuring.
Configure...
option
3-13
8. If the value displayed in the
Address
edit box is not correct, type the
correct value into the box. You may enter the address in decimal or
hexadecimal using the c–notation for hex, (that is, 768 decimal =
0x300 hexadecimal).
9. Choose the correct options for the
Counter/Timer Sections
by first clicking on the appropriate radio
Analog, Digital,
and
button in the middle of the dialog box and then completing the group
of dialog fields in the lower third of the dialog box. Be sure to click
on both the
Input
and
Output
radio buttons for the
Analog
and
Digital
groups to see all the dialog fields.
10. After you have made all your selections, save the configuration
parameters by clicking on the OK button. This will create or update
the configuration file, <device>.INI, in the Windows directory.
11. Repeat the preceding steps starting at step 5, for each Logical Device
you wish to configure.
You can use DriverLINX to verify board operation
1. To physically initialize the DAS-1200, select
Device/Initialize
from
the main menu in Learn DriverLINX.
2. The first time the DAS-1200 is initialized, or after a configuration
change, DriverLINX runs a diagnostic program to verify the
operation and accuracy of the configuration settings.
You are now ready to make I/O connections. Refer to Chapter 4 for
descriptions of common I/O accessories and connections for DAS-1200
Series boards.
3-14Setup and Installation
4
Cabling and Wiring
In most applications, you use accessories to connect external I/O devices
to the DAS-1200 Series boards. Keithley accessories extend signals from
the main I/O connector (J1) to corresponding screw terminals of the
accessory.
You access the 24 bits of parallel bidirectional digital I/O by using a flat
ribbon cable known as the PIO cable. The board end of the PIO cable
attaches to the PIO cable connector (J4) on the DAS-1200 Series board.
The other end of the PIO cable is fitted with a standard 37-pin D-type
connector and a mounting flange that installs in the connector panel next
to the main I/O connector (J1). The PIO cable comes with all DAS-1200
Series boards.
This chapter describes the cabling and accessories required for attaching
field wiring to your DAS-1200 Series boards.
Caution:
any attached accessories before making connections to DAS-1200 Series
boards.
To avoid electrical damage, turn off power to the computer and
4-1
Attaching Screw Terminal Connectors and
Accessories
You can use the following screw terminal connectors and accessories to
simplify connection of field wiring to DAS-1200 Series boards:
●
STC-37 Screw Terminal Connector; your application may require two
connectors
●
STP-37 Screw Terminal Panel; your application may require two
connectors
●
STA-16 Screw Terminal Accessory
●
STA-U Universal Screw Terminal Accessory
The following sections describe how to attach these accessories to the
DAS-1200 Series boards.
Attaching an STC-37
The screw terminals on the STC-37 screw terminal connector allow you
to connect field wiring to a DAS-1200 Series board. The screw terminals
accept wire sizes 12-22 AWG.
To connect an STC-37 to the main I/O connector (J1) of a DAS-1200
Series board, directly attach the 37-pin connector on the STC-37 to the
main I/O connector (J1). Figure 4-1 illustrates the connection of an
STC-37 to a DAS-1200 Series board.
Note:
Your application may require connections to the main I/O
connector (J1) and connections to the PIO cable connector (J4). When
two STC-37 connectors are required, you should consider wire sizes and
service area requirements. These considerations may suggest the use of an
alternate accessory.
4-2Cabling and Wiring
STC-37 Screw
Terminal Connector
21
37
17
16
DAS-1200 Series board
J1
5
4
pin 1
1
strain relief
Figure 4-1. Attaching an STC-37 Screw Terminal Connector
The screw terminals are labeled from 1 to 37 and correspond directly to
the functions of the pins on the main I/O connector (see Figure 4-2). For
example, since pin 25 is assigned to IP0/TRIG 0/XPCLK, use screw
terminal 25 to attach a digital signal to bit 0 of the standard digital input
port.
34
33
22
4-3
Rear View
LL GNDPin 19
Ch0 LO IN / *Ch8 HI INPin 18
Ch1 LO IN / *Ch9 HI INPin 17
Ch2 LO IN / *Ch10 HI IN Pin 16
Ch3 LO IN / *Ch11 HI IN Pin 15
Ch4 LO IN / *Ch12 HI IN Pin 14
Ch5 LO IN / *Ch13 HI IN Pin 13
Ch6 LO IN / *Ch14 HI IN Pin 12
Ch7 LO IN / *Ch15 HI IN Pin 11
NOT CONNECTEDPin 10
Figure 4-2. Pin Assignments of the Main I/O Connector (J1)
When using an STC-37 to make connections to the bidirectional digital
I/O, first attach the board end of the PIO cable to the PIO cable connector
(J4) on the DAS-1200 Series board, then install the 37-pin D-type
connector of the PIO cable in the connector panel next to the main I/O
connector (J1) of the DAS-1200 Series board, and finally attach the
second STC-37 to the 37-pin D-type connector of the PIO cable. For
more information about making field connections, see “Connecting
Analog Signals.”
Attaching an STP-37
The screw terminals on the STP-37 screw terminal panel allow you to
connect field wiring to DAS-1200 Series boards. The STP-37 contains the
following components:
A 37-pin male connector for cabling to the main I/O connector of a
●
DAS-1200 Series board.
4-4Cabling and Wiring
Labeled screw terminals for connecting sensor outputs and test
●
equipment. These terminals accept wire sizes 12-22 AWG.
You attach an STP-37 screw terminal panel to the main I/O connector (J1)
on the DAS-1200 Series board with a C-1800 or S-1800 cable. The
C-1800 is the unshielded version of the cable; the S-1800 is the shielded
version of the cable. Figure 4-3 shows how to attach an STP-37 to a
DAS-1200 Series board.
DAS-1200 Series board
The screw terminals are labeled 1 to 38 and correspond directly to the
functions of the board connector. See Figure 4-2 for the pin assignments
of the main I/O connector (J1).
When using an STP-37 to make connections to the bidirectional digital
I/O, first attach the board end of the PIO cable to the PIO cable connector
(J4) on the DAS-1200 Series board, then install the 37-pin D-type
connector of the PIO cable in the connector panel next to the main I/O
connector (J1) of the DAS-1200 Series board, and finally attach the
STP-37 to the 37-pin D-type connector of the PIO cable. See Figure 4-8
for the pin assignments of the PIO cable.
C-1800 / S-1800 cable
J1
Figure 4-3. Attaching an STP-37
J1
STP-37
1
19
20
38
4-5
Attaching an STA-16
The screw terminals on the STA-16 screw terminal accessory allow you to
connect field wiring to DAS-1200 Series boards. The STA-16 contains the
following components:
●
Two 37-pin male connectors. One for cabling to the main I/O
connector of a DAS-1200 Series board and a second for
daisy-chaining additional accessories.
●
Labeled screw terminals for connecting sensor outputs and test
equipment. These terminals accept wire sizes 12-22 AWG.
A breadboard area for user-installed circuitry.
●
You attach an STA-16 scre w terminal accessory to the main I/O connector
(J1) on the DAS-1200 Series board with a C-1800 or S-1800 cable. The
C-1800 is the unshielded version of the cable; the S-1800 is the shielded
version of the cable. Figure 4-4 shows how to attach an STA-16 to a
DAS-1200 Series board.
DAS-1200 Series board
J1
C-1800 / S-1800 cable
pin 1
pin 1
J1
J2
STA-16
Figure 4-4. Cabling and Connections for Attaching an STA-16
4-6Cabling and Wiring
Figure 4-5 shows the screw terminal names on the STA-16.
CH 0 HI
0 LO/8 HI
LL GND
CH 1 HI
1 LO/9 HI
LL GND
J2J1
+5V
OP 3
OP 2
OP 1
OP 0
GND
Figure 4-5. STA-16 Terminal Names
Attaching an STA-U
CH 2 HI
2 LO/10 HI
IP 3
IP 3
LL GND
CH 3 HI
IP 3
IP 3
LL GND
3 LO/11 HI
OUT
GND
CTR 2
CH 4 HI
4 LO/12 HI
OUT
CTR 0
GND
LL GND
CH 5 HI
USER 1
CTR 0 IN
5 LO/13 HI
LL GND
USER 2
LL GND
CH 6 HI
6 LO/14 HI
OUT
D/A 0
D/A 0
LL GND
REF IN
-5 V REF
CH 7 HI
7 LO/15 HI
D/A 1
D/A 1
REF IN
LL GND
OUT
GND
The screw terminals on the STA-U universal screw terminal accessory
allow you to connect field wiring to the D AS-1200 Series board PIO cable
connector (J4). The STA-U contains the following components:
A 37-pin male connector for cabling to the PIO cable connector (J4).
●
Labeled screw terminals for connecting digital inputs and outputs.
●
These terminals accept wire sizes 12-22 AWG.
A breadboard area for user-installed circuitry.
●
First, attach the board end of the PIO cable to the PIO cable connector
(J4) on the DAS-1200 Series board. Next, install the 37-pin D-type
connector of the PIO cable in the connector panel next to the main I/O
connector (J1) of the DAS-1200 Series board. Finally, attach connector J2
on the STA-U screw terminal accessory to the 37-pin D-type connector of
the PIO cable with a C-1800 or S-1800 cable. The C-1800 is the
unshielded version of the cable; the S-1800 is the shielded version of the
cable.
4-7
Figure 4-6 shows how to attach an STA-U to a DAS-1200 Series board.
J4PIO cable
DAS-1200 Series board
C-1800 / S-1800 cable
pin 1
pin 1
J1
Figure 4-6. Cabling and Connections for Attaching an STA-U
Figure 4-7 shows the screw terminal names on an STA-U. The screw
terminals map directly to the pins of the PIO cable connector (J4) shown
in Figure 4-8.
37
36
35
34
33
32
31
30
29
28
27
26
user breadboard connections
25
J2 J3
STA-U
J2J1
J3
1
2
6
534
7
8
9
10
11
12
13
14
15
16
18
17
1920212223
24
Figure 4-7. STA-U Terminal Names
4-8Cabling and Wiring
Rear View
DIG.COM.Pin 19
+5 VPin 18
DIG. COM.Pin 17
NOT CONNECTEDPin 16
DIG. COM.Pin 15
NOT CONNECTEDPin 14
Figure 4-8. Pin Assignments of PIO Cable Connector (J4)
Attaching Expansion Accessories
Pin 37PA 0
Pin 36PA 1
Pin 35PA 2
Pin 34PA 3
Pin 33PA 4
Pin 32PA 5
Pin 31PA 6
Pin 30PA 7
Pin 29PC 0
Pin 28PC 1
Pin 27PC 2
Pin 26PC 3
Pin 25PC 4
Pin 24PC 5
Pin 23PC 6
Pin 22PC 7
Pin 21DIG. COM.
Pin 20+5 V
PORT A
PORT CH
PORT CL
You can use the following expansion accessories to increase the number
of channels available and add signal conditioning to your application:
●
EXP-16
●
EXP-16/A
EXP-GP
●
The following sections describe how to attach these expansion
accessories to DAS-1200 Series boards.
4-9
Attaching an EXP-16 or EXP-16/A Expansion Accessory
Each expansion multiplexer/amplifier accessory provides up to 16 analog
input channels (labeled 0 to 15). Table 4-1 lists the terminal names used
on EXP-16 and EXP-16/A expansion accessories.
Table 4-1. EXP-16 and EXP-16/A Terminal Names
Terminal NameSignal
LL GND
CHn HI
CHn LO
DAS-1200 Series board
low-level ground
positive input; where n indicates the channel number
negative input; where n indicates the channel number
To connect an EXP-16 or EXP-16/A to a DAS-1200 Series board, attach
one end of an S-1600 cable to the DAS-1200 Series main I/O connector
(J1) and the other end of the cable to the J1 connector on the EXP-16 or
EXP-16/A. Figure 4-9 illustrates the connection of an EXP-16 to a
DAS-1200 Series board.
J2
J1
S-1600 Cable
J1
pin 1
pin 1
EXP-16
Figure 4-9. Attaching an EXP-16 or EXP-16/A Expansion Accessory
4-10Cabling and Wiring
Note:
The S-1600 cable must be used to connect the first EXP to the
DAS-1200 Series board.
Refer to the EXP-16 and EXP-16/A expansion board documentation for
more information about these accessories and instructions for installing
the PG-408A option on the board.
Caution:
Do not attach an EXP-16 or EXP-16/A to the PIO cable
connector (J4).
Attaching an EXP-GP Expansion Accessory
Each EXP-GP expansion multiplexer/signal conditioner board provides
up to eight analog input channels (labeled 0 to 7). Table 4-2 lists the
terminal names used on each EXP-GP channel.
Table 4-2. EXP-GP Terminal Names
Terminal NameSignal
+IEXCpositive current excitation
+SENSEpositive input
−
P
−
IEXC
SENSE
−
+Ppositive voltage excitation
negative voltage excitation
negative current excitation
negative input
4-11
To connect an EXP-GP to a DAS-1200 Series board, attach one end of an
S-1600 cable to the DAS-1200 Series main I/O connector (J1) and the
other end of the cable to the J1 connector on the EXP-GP. Figure 4-10
illustrates the connection of an EXP-GP to a DAS-1200 Series board.
DAS-1200 Series board
Figure 4-10. Attaching an EXP-GP Expansion Accessory
Refer to the EXP-GP expansion board documentation for more
information about this expansion accessory.
J1
S-1600 cable
pin 1
pin 1
J1
J2
EXP-GP
Attaching Multiple Expansion Accessories
You can daisy-chain up to eight EXP-16, EXP-16/A, and/or EXP-GP
expansion accessories to provide up to 128 analog input channels.
As shown in Figure 4-11, you connect the first expansion accessory to the
DAS-1200 Series board by attaching one end of an S-1600 cable to the
main I/O connector (J1) on the DAS-1200 Series board and the other end
of the cable to the J1 connector on the expansion accessory.
To connect additional expansion boards, attach one end of a C-1800 or
S-1800 cable to the J2 connector on the previous expansion board and the
other end of the cable to the J1 connector on the next expansion board in
the chain.
Notes:
Each EXP-16, EXP-16/A, or EXP-GP expansion accessory is
associated with an analog input channel on the DAS-1200 Series board.
You specify the associated DAS-1200 input channel by setting a jumper
on each expansion accessory. Make sure that you use a unique jumper
setting for each expansion accessory you are using. Refer to your
expansion accessory documentation for more information.
Make sure that you attach EXP-16 and EXP-16/A expansion accessories
before EXP-GP expansion accessories.
4-13
You can access the remaining functions of the DAS-1200 Series board by
including an STA-16 or STA-U screw terminal accessory in the daisy
chain. Figure 4-12 illustrates how to connect two EXP-16 expansion
accessories, one EXP-GP expansion accessory, and an STA-16 (or
STA-U) screw terminal accessory to a DAS-1200 Series board.
J1
DAS-1200
Series board
C-1800
J2
ST A-16 or
ST A-U
J1
S-1600
J2J1
EXP-16
C-1800
J1
J2J1
C-1800
EXP-16
Figure 4-12. Attaching Multiple Expansion Accessories with an STA-16 or STA-U
Note:
As shown in Figure 4-12, when you use an STA-16 (or STA-U) to
access unused signals, you must attach the STA-16 (or STA-U) first with
a C-1800 or S-1800 cable.
Attaching an ISO-4 Accessory
The ISO-4 is a high speed, universal expansion interface and isolation
amplifier. The ISO-4 contains four fully isolated, differentially measured
input channels supporting seven jumper-selectable gains of 1, 2, 10, 50,
100, 200, and 1000 on a per channel basis. You can further customize
gains to meet your specific requirements with user-installable resistors.
EXP-GP
Refer to the
ISO-4 User’s Guide
for more information about ISO-4
features and applications.
To connect an ISO-4 to a DAS-1200 Series board, attach one end of an
S-1600 cable to the DAS-1200 Series main I/O connector (J1) and the
other end of the cable to the J1 connector on the ISO-4 accessory. Figure
4-13 illustrates the connection of an ISO-4 accessory to a DAS-1200
Series board.
4-14Cabling and Wiring
J1
S-1600 Cable
CJC channel
J2
J1
output channel
DAS-1200 Series board
Figure 4-13. Attaching an ISO-4 Accessory
Attaching SSH Accessories
Simultaneous sample-and-hold (SSH) accessories allow you to acquire
analog input data from multiple inputs simultaneously. SSH accessories
available for DAS-1200 Series boards are the SSH-4/A and the SSH-8.
Figure 4-14 shows a diagram of a typical measurement system using an
SSH-8.
DAS board
Figure 4-14. A Typical SSH-8 Application
SSH-8
ISO-4
Analog Inputs
The following subsections describe how to attach SSH-4/A and SSH-8
boards to DAS-1200 Series boards.
4-15
Attaching an SSH-4/A
The SSH-4/A is a 4-channel simultaneous sample-and-hold board whose
functions and capabilities are described in the
SSH-4/A serves as a front-end analog interface for DAS-1200 Series
boards.
Figure 4-15 shows how to attach the SSH-4/A to a DAS-1200 Series
board.
SSH-4/A User Guide
. The
DAS-1200 Series board
Figure 4-15. Attaching an SSH-4/A Accessory
Additional SSH-4/A accessories are attached in daisy-chain fashion with
a CACC-2000 cable.
Attaching an SSH-8
The SSH-8 is a high performance 8-channel simultaneous
sample-and-hold board whose functions and capabilities are described in
the
SSH-8 User’s Guide
for DAS-1200 Series boards.
J1
C-1800 Cable
J4
J2
J1
SSH-4/A
. The SSH-8 serves as a front-end analog interface
Analog Inputs
Figure 4-16 and Figure 4-17 show how to attach SSH-8 boards to a
DAS-1200 Series board.
4-16Cabling and Wiring
DAS-1200
Series board
S-1800 or
C-1800
SSH-8
Optional +5 V power and
ground.
Analog Inputs plus
optional external pacer
clock (EXT CLK IN)
STC-SSH-8 or user-supplied cable
DAS-1200
Series board
S-1800 or
C-1800
SSH-8
SSH-8-DC
SSH-8
MANDATORY +5 V
power and ground
STC-SSH-8 or user-supplied
cable for analog Inputs plus
optional external pacer clock
(EXT CLK IN)
STC-SSH-8 or user-supplied
cable for analog Inputs
Figure 4-16. Attaching SSH-8 Accessories
When you use the cabling shown in Figure 4-16, observe the following
rules:
●
For best results, the length of any cable should not exceed 30 inches.
The length of two cables should not exceed 36 inches. Total length for
all cables in series should not exceed 50 inches. Total cable length
does not include analog input cables.
●
You can use the STC-SSH-8 screw terminal interface instead of a
cable.
Use eight feet maximum of #18 AWG wire (or heavier) for optional
●
external power and ground.
●
When daisy-chaining two SSH-8 accessories to a DAS-1200 Series
board, put the first in master mode and the second in slave mode.
Optional channel jumpers are 0 to 7 for the first SSH-8 accessory and
●
8 to 15 for the second.
4-17
Where the S-1800 cable is called out, other options include C-1800,
●
S-1801, and C-1801. Crosstalk, shielding, and cost tradeoffs are
factors in the selection of these options.
DAS-1200
Series board
S-1800 or
C-1800
DAS-1200
Series board
S-1800 or
C-1800
SSH-8-DC
Digital I/O
S-1800 or
C-1800
SSH-8
S-1800 or
C-1800
STA-16 accessory
SSH-8
SSH-8
STA-16 accessory
Optional +5 V power and
ground
Analog Inputs plus
optional external pacer
clock (EXT CLK IN)
STC-SSH-8 or user-supplied cable
MANDATORY
+5 V power and ground
STC-SSH-8 or user-supplied
cable for analog Inputs plus
optional external pacer clock
(EXT CLK IN)
STC-SSH-8 or user-supplied
cable for analog Inputs
Note that only one EXT CLK
IN source is usable
Digital I/O
Figure 4-17. Attaching SSH-8 and STA-16 Accessories
Caution:
Do not connect analog inputs to STA-16 pins that are driven by
SSH-8 outputs.
Refer to the
4-18Cabling and Wiring
SSH-8 User’s Guide
for more information.
Attaching an MB Series Backplane
MB Series modules are ideally suited to applications where monitoring
and control of temperature, pressure, flow, and other analog signals are
required. Figure 4-18 shows a block diagram of a typical MB Series
measurement and control application.
mV , V, Thermocouple,
RTD, Strain Gauge,
4–20 mA / 0–20 mA
Sensors,
Monitors
Process or
Equipment
Controls
(Valves, etc.)
4–20 mA / 0–20 mA
Figure 4-18. Typical Measurement and Control Application
Input
Module
MB SERIES
MODULES
Output
Module
0 to +5 V / ±5 V
A/D
Analog I/O
D/A
0 to +5 V / ±5 V
Computer
4-19
Table 4-3 provides a brief summary of the backplanes available for use
with MB Series modules.
Table 4-3. MB Series Backplanes
ModelDescription
MB01Holds up to 16 modules and mounts in a 19-inch equipment rack.
Provides direct channel-to-channel connection to a DAS-1200 Series
board making it suitable for high-speed, high-resolution applications.
MB02Holds up to 16 modules and mounts in a 19-inch equipment rack. Up
to four MB02s can be multiplexed together, providing a total of 64
channels. This makes it suitable for larger systems.
STA-MBHolds up to four modules and provides general-purpose screw
terminal connections for all other signals on the DAS-1200 Series
board.
Attaching an MB01 Backplane
Use the C16-MB1 cable to connect a DAS-1200 Series board to an MB01
backplane. This cable connects MB01 channels 0 through 15 to analog
input channels 0 through 15 on the DAS-1200 Series board. Refer to
Figure 4-19 for a cabling diagram.
DAS-1200
Series
board
C16-MB1
MB01
Use connector P1 or P2
(identical pinouts)
Figure 4-19. Attaching an MB01 Backplane
Note: The channel connections are single-ended. Make sure that the
DAS-1200 Series board is set for 16-channel, single-ended operation.
4-20Cabling and Wiring
Attaching an MB02 Backplane
Figure 4-20 shows how to connect the DAS-1200 Series to up to four
MB02 backplanes. The STA-SCM16 interface connects one MB02 board
to one analog input channel of the DAS-1200 Series board. One C-2600
cable connects each MB02 to the STA-SCM16, and the C-1800 cable
connects the STA-SCM16 to the DAS-1200 Series board.
DAS-1200
Series board
HOST PC
C-1800
STA-SCM16
MB02
MB02
MB02
C-2600
(four cables)
MB02
Figure 4-20. Attaching Multiple MB02 Backplanes
4-21
Figure 4-21 shows how the STA-SCM16 connects DAS-1200 Series
boards with MB02 backplanes.
MB02 Backplane Interfaces
Vread
Vwrite
A/D CH 0 IN
D/A CH 0 OUT
A/D CH 1 IN
D/A CH 1 OUT
A/D CH 2 IN
A/D CH 3 IN
Vread
Vwrite
Vread
Vread
DAS-1200 Interface
0123
Backplane Connectors
STA-SCM16
Figure 4-21. MB02 I/O Connections
The four digital output lines on the DAS-1200 Series board select one of
the 16 MB02 channels. For example, if you set the digital output lines to
1000 (8 decimal), MB02 channel 8 is selected on all four backplanes.
Analog input channels 0 to 3 on the DAS-1200 Series board map directly
to the connectors labeled 0 to 3 on the STA-SCM16.
In this arrangement, the channel connections are single-ended. Make sure
that the DAS-1200 Series board is set for single-ended, 16-channel
operation.
Refer to the MB Series User’s Guide for more information.
4-22Cabling and Wiring
Connecting Analog Signals
This section contains precautionary advice to consider before making
analog input connections. The section also shows some circuits for wiring
signal sources to input channels of DAS-1200 Series boards.
While the circuit diagrams show direct connections to channel input pins
of the main I/O connector, you must make actual connections through
corresponding inputs of an accessory.
The circuit diagrams represent a single signal source wired to a single
channel (channel n). In reality, you can wire eight separate signal sources
to eight differential inputs or 16 separate signal sources to 16
single-ended inputs.
If you expect to use DAS-1201 boards at high gains, read the
precautionary information in the following section. Other considerations
for I/O connections are offered under “Additional Precautions” on page
4-24.
Precautions for Using the DAS-1201 Board at High Gains
Operating DAS-1201 boards at gains of 100 or 500 can lead to problems
if your application is unable to cope with noise. At a gain of 500, with a
bipolar input range of
corresponds to 4.88
bandwidth of this board, analog noise and performance degradation come
easily unless you take precautions to avoid them. The following collection
of ideas and suggestions is aimed at avoiding these problems:
●Operate DAS-1201 boards in 8-channel differential mode. Using the
board in 16-channel, single-ended mode at high gains introduces
enough ground-loop noise to produce large fluctuations in readings.
−5.0 V to +5.0 V, each bit of A/D output
µV of analog input. Thus, with the high speed and
4-23
●Minimize noise from crosstalk and induced-voltage pickup in the flat
cables and screw terminal accessories by using shielded cable.
Connect the shield to LL GND and the inner conductors to Channel
LO and HI. Channel LO and LL GND should have a DC return (or
connection) at some point; this return should be as close to the signal
source as possible. Induced noise from RF and magnetic fields can
easily exceed tens of microvolts, even on one- or two-foot cables;
shielded cable eliminates this problem.
●Avoid bi-metallic junctions in the input circuitry. For example, the
kovar leads, used on reed relays, typically have a thermal emf to
copper of 40
variations caused by air currents and so on.
●Consider filtering. This approach can use hardware (resistors,
capacitors, and so on) but is often accomplished more easily with
software. Instead of reading the channel once, read it 10 or more
times in quick succession and average the readings. If the noise is
random and gaussian, it will be reduced by the square-root of the
number of readings.
Additional Precautions
µV/˚C. Thermals can introduce strange random
Do not mix your data acquisition inputs with the AC line, or you risk
damaging the computer. Data acquisition systems provide access to
inputs of the computer. An inadvertent short between data and power lines
can cause extensive and costly damage to your computer. The
manufacturer can accept no liability for this type of accident. To prevent
this problem, use the following precautions:
●Avoid direct connections to the AC line.
●Make sure all connections are tight and sound so that signal wires are
not likely to come loose and short to high voltages.
●Use isolation amplifiers and transformers where necessary.
4-24Cabling and Wiring
Connecting a Signal to a Single-Ended Analog Input
Figure 4-22 shows the connections between a signal source and a channel
of a DAS-1200 Series board configured for single-ended input mode.
CHANNEL n
HIGH
DAS-1200 Series board
LL GND
Figure 4-22. Connections for Wiring a Signal Source to a DAS-1200 Series Board
Configured for Single-Ended Inputs
The main I/O connector (J1) contains the following two ground
connections:
●POWER GND is the noisy or “dirty” ground that carries all digital
signal and power supply currents.
+
-
Signal
Source
●LL GND or low level ground is the ground reference for all analog
input functions and it only carries signal currents that are less than a
few mA.
Due to connector contact resistance and cable resistance, there may be
many millivolts difference between the two grounds although they are
connected to each other.
Note: When you wire signals to the analog input channels, you are
advised to wire all unused channels to LL GND. This action prevents the
input amplifiers from saturating, and it ensures the accuracy of your data.
4-25
Connecting a Signal to a Differential Analog Input
This section describes common connection schemes for differential
inputs. The section also discusses the principles for avoiding ground
loops.
Common Connection Schemes for Differential Inputs
Figure 4-23 shows three methods of wiring a signal source to a channel of
a DAS-1200 Series board configured for differential input mode.
DAS-1200 Series board
DAS-1200 Series board
DAS-1200 Series board
Channel n High
Channel n Low
LL GND
Where Rs > 100 ohms
Rb = 2000 R
Channel n High
Channel n Low
LL GND
Where Rs < 100 ohms
Rb > 1000 R
Channel n Low
LL GND
Channel n High
R
R
x
+
Signal
R
s
R
R
b
b
Source
-
s
+
Signal
R
s
R
b
Source
-
s
a
R
a
arm
R
a
bridge
null
+
supply
-
DC
Figure 4-23. Three Methods for Wiring Differential Inputs
4-26Cabling and Wiring
The upper two circuits of the diagram require the addition of resistors to
provide a bias-current return. You can determine the value of the bias
return resistors (R
) from the value of the source resistance (Rs), using the
b
following relationships:
●When R
is greater than 100 Ω, use the connections in the upper
s
circuit. The resistance of each of the two bias return resistors must
equal 2000 R
●When R
.
s
is less than 100 Ω, use the connections in the middle circuit.
s
The resistance of the bias return resistor must be greater than 1000 R
In the lower circuit, bias current return is inherently provided by the
source. The circuit requires no bias resistors.
Avoiding Ground Loops with Differential Inputs
Very often, the signal-source ground and the DAS-1200 Series board
ground are not at the same voltage level because of the distances between
equipment wiring and the building wiring. This dif ference is referred to as
a common-mode voltage (Vcm) because it is normally common to both
sides of a differential input (it appears between each side and ground).
Since a differential input responds only to the difference in the signals at
its high and low inputs, its common-mode voltages cancel out and leave
only the signal. However, if your input connections contain a ground
loop, your input could see the sum of the signal-source and
common-mode voltages. Figure 4-24 shows the proper way to connect a
differential input while Figure 4-25 illustrates the effect of a ground loop.
.
s
CHANNEL n HIGH
DAS-1200 Series board
Do not connect n LOW to LL GND at the computer
CHANNEL n LOW
LL GND
V
g2
V
cm =
V
cm
V
V
g2
g1 -
+
E
s
-
Signal
Source
Ground
V
g1
Figure 4-24. A Differential Input Configuration that Avoids a Ground Loop
Signal
Source
4-27
DAS-1200 Series board
CHANNEL n HIGH
CHANNEL n LOW
V
cm
+
Signal
E
s
Source
-
LL GND
V
g2
V
cm =
V
V
g2
g1 -
Signal
Source
Ground
V
g1
Figure 4-25. Differential Input Configuration with a Ground Loop
4-28Cabling and Wiring
5
DriverLINX Analog I/O Panel
The DriverLINX Analog I/O Panel is an application that demonstrates
analog input/output using DriverLINX. With the Analog I/O Panel you
can:
Analyze analog signals using the two-channel Oscilloscope.
●
Measure analog voltages using the Digital Volt Meter.
●
●
Generate Sine, Square and Triangle waves using the SST Signal
Generator.
●
Output DC Level voltages using the Level Control.
The Analog I/O Panel is useful for:
●
Testing the DAS-1200 DriverLINX installation and configuration.
●
Verifying signal inputs to your DAS-1200 board.
Sending test signals to external devices.
●
To access this DriverLINX Analog I/O Panel:
1. Start the Analog I/O P anel with the “AIO Panel” item on the Windo ws
start menu. Then perform the following steps:
2. Click the [...] button in the Driver Selection section.
3. Select the driver for your board using the
4. Click
OK.
Open DriverLINX
dialog.
5-1
5. Select the Logical Device you want to operate by dragging the pointer
in the Device Selection section. The Analog I/O Panel displays the
Scope, Meter, SST, and Level control tabs, depending on the
capabilities of your DAS-1200 board.
6. The Scope uses two analog input channels, referred to as ChA and
ChB. Drag the channel selectors in the AI Channel Mapping section
to map them to different channel numbers.
7. The SST Signal Generator uses two analog output channels, referred
to as ChA and ChB. Drag the channel selectors in the AO Channel
Mapping section to map them to different channel numbers.
You can now select the Scope, Meter, SST and Level Control tabs to
operate your DAS-1200 board.
Test Panel Application
Depending upon the DriverLINX drivers you have installed on your
system, you will have one or more of the following example applications:
●
Single–Value AI
Single–Value AO
●
PIO Panel
●
CTM Test Bench
●
for analog input
for analog output
for digital input and output
for counter/timer applications.
To access this DriverLINX Test Panel, select Test Panel with the “Test
Panel” item on the Windows start menu.
5-2DriverLINX Analog I/O Panel
Your DAS-1200 Series board is initially calibrated at the factory. You are
advised to check the calibration of a board every six months and to
calibrate again when necessary . This section provides the information you
need to calibrate a DAS-1200 Series board.
Equipment Requirements
The equipment requirements for calibrating a DAS-1200 Series board are
as follows:
A digital voltmeter accurate to a minimum of 5-1/2 digits
●
6
Calibration
●
An adjustable ±10 V power source
Potentiometers and Test Points
Figure 3-1 on page 3-3 shows the locations of the potentiometers and test
points that are used during the calibration of a DAS-1200 Series board.
The calibration utility, described in the next section, directs you to
components and explains what to do with them during the calibration
process.
6-1
Calibration Utility
DriverLINX Calibration Utility will guide you through the calibration
procedure. Before calibration, specify the following parameters in the
setup panel to get the correct instructions:
Logical Device
●
Accessory
●
— Connection method used to connect the board to the
calibration stimulus.
Shorted channel
●
●
Voltage Channel
calibration voltage levels
●
Calibration range
— Board’s device number, model and address.
— Input channel to be “shorted” high to low
— Input channel to use to apply the various
— Input range to be calibrated.
6-2Calibration
If your DAS-1200 Series board is not operating properly, use the
information in this section to isolate the problem. If the problem appears
serious enough to warrant technical support, refer to “Technical Support”
on page 7-6 for information on how to contact an applications engineer.
Problem Isolation
If you encounter a problem with a DAS-1200 Series board, use the
instructions in this section to isolate the cause of the problem before
calling Keithley for technical support.
7
Troubleshooting
Identifying Symptoms and Possible Causes
Use the troubleshooting information in Table 7-1 to try to isolate the
problem. Table 7-1 lists general symptoms and possible solutions for
problems with DAS-1200 Series boards.
Using the DriverLINX Event Viewer
The DriverLINX Event Viewer displays the Windows system event log.
Applications and hardware drivers make entries in the system e v ent log to
assist in predicting and troubleshooting hardware and software problems.
DriverLINX uses the event log to report problems during driver loading
or unexpected system errors. The event log can assist in troubleshooting
resource conflicts and DriverLINX configuration errors. If you are having
trouble configuring or initializing a Logical Device, check the event log
for information from the DriverLINX driver.
7-1
Using the DriverLINX Event Viewer , you can vie w Driv erLINX ev ent log
entries under Windows 95/98 or Windows NT. DriverLINX event log
entries can help you or technical support troubleshoot data-acquisition
hardware and software problems.
Device initialization error messages
During device initialization, DriverLINX performs a thorough test of all
possible subsystems on the DAS-1200 Series board as well as the
computer interface. If DriverLINX detects any problems or unexpected
responses, it reports an error message to help isolate the problem. The
device initialization error messages fall into three basic categories:
“Device not found”
●
— Board address does not match hardware
setting or conflicts with another board. Verify the board’s address
settings. Also, don’t confuse hexadecimal with decimal addresses in
the DriverLINX
●
“Invalid IRQ le vel”
Device Configure
or
“Invalid DMA le vel”
dialog box.
— Selected level does
not match hardware setting, conflicts with another board’ s IRQ/DMA
levels, or is dedicated to the computer’s internal functions (COM
port, disk drive controller, network adapter, etc.).
●
“Hardware does not match configuration”
— Operating
mode/range switch or jumper setting does not match selection(s)
made in the DriverLINX
Device Configuration
dialog box.
7-2Troubleshooting
Table 7-1. Troubleshooting Information
SymptomPossible CausePossible Solution
Board does not
respond
Intermittent
operation
Base address is incorrect.Ensure that the base address switch on
the board is set correctly and that your
program references the same base
address. If the base address is set
correctly, ensure that no other computer
device is using any of the I/O locations
beginning at the specified base address.
See Table 3-2 for a list of standard
address assignments. If necessary,
reconfigure the base address. Refer to
page 3-5 for instructions on setting the
base address.
The interrupt level is incorrect.Ensure that no other computer device is
using the interrupt level specified in your
program. If necessary, reset the interrupt
level.
The board is incorrectly aligned
in the accessory slot.
The board is damaged.Contact the Keithley Hardware
The most common cause of this
problem is that the I/O bus speed
is in excess of 8 MHz.
Check installation.
Applications Engineering Department;
see page 7-6.
Reduce I/O bus speed to a maximum of
8 MHz (to change the I/O bus speed, run
BIOS setup). See the documentation for
your computer for instructions on
running BIOS setup.
Vibrations or loose connections
exist.
The board is overheating.Check environmental and ambient
Electrical noise exists. Provide better shielding or reroute
Bus cycles require wait state.Enable wait states on DAS-1200 Series
Cushion source of vibration and tighten
connections.
temperature. See the documentation for
your computer.
wiring.
board.
7-3
Table 7-1. Troubleshooting Information (cont.)
SymptomPossible CausePossible Solution
Data appears to be
invalid
Computer does not
boot
The most common cause of this
problem is that the I/O bus speed
is in excess of 8 MHz.
An open connection exists.Check wiring to screw terminal.
Another device is using the
specified base address.
Board not seated properly.Check that the board is properly
The base address setting of the
DAS-1200 Series
conflicts with that of another
device.
The power supply of the host
computer is too small to handle
all the devices installed in your
system.
board
Reduce I/O bus speed to a maximum of
8 MHz (to change the I/O bus speed, run
BIOS setup). See the documentation for
your computer for instructions on
running BIOS setup.
Reconfigure the base address of the
DAS-1200 Series
page 3-5 for more information. Check
the I/O assignments of other system
devices and reconfigure, if necessary.
installed.
Verify that the base address setting of
your DAS-1200 Series board is unique.
Check the needs of all system devices
and obtain a larger power supply if
necessary.
board; refer to
System lockupA timing error occurred.Press
[Ctrl] + [Break]
.
If your board is not operating properly after using the information in
Table 7-1, continue with the next two sections to further isolate the
problem.
Testing the Board and Host Computer
To isolate the problem to the DAS-1200 Series board or to the host
computer, use the following steps:
1. Turn the power to the host computer OFF, and remove power
connections to the computer.
7-4Troubleshooting
Caution:
your board and/or computer.
2. While keeping connections to accessories intact, unplug the
accessory connector(s) or cable(s) from the DAS-1200 Series
board(s).
3. Remove the DAS-1200 Series board(s) from the computer and
visually check for damage. If a board is obviously damaged, refer to
“Technical Support” on page 7-6 for information on returning the
board.
4. With the DAS-1200 Series board(s) out of the computer, check the
computer for proper operation. Power up the computer and perform
any necessary diagnostics.
At this point, if you have another DAS-1200 Series board that you know
is functional, you can test the slot and I/O connections using the
instructions in the next section. If you do not have another board, refer to
page 7-6 for instructions on calling Keithley Technical Support.
Removing a board with the power ON can cause damage to
Testing the Accessory Slot and I/O Connections
When you are sure that the computer is operating properly, test the
computer accessory slot and I/O connections using another DAS-1200
Series board that you know is functional. To test the computer accessory
slot and the I/O connections, follow these steps:
1. Remove computer power again, and install a DAS-1200 Series board
that you know is functional. Do not make any I/O connections.
2. Turn computer power ON and check operation with the functional
board in place. This test checks the computer accessory slot. If you
were using more than one DAS-1200 Series board when the problem
occurred, use the functional board to test the other slot(s) as well.
3. If the accessory slots are functional, use the functional board to check
the I/O connections. Reconnect and check the operation of the I/O
connections, one at a time.
7-5
4. If operation fails for an I/O connection, check the individual inputs
one at a time for shorts and opens.
5. If operation remains normal to this point, the problem is in the
DAS-1200 Series board(s) originally in the computer. If you were
using more than one board, try each board one at a time in the
computer to determine which is faulty.
6. If you cannot isolate the problem, refer to the next section for
instructions on obtaining assistance.
Technical Support
Before returning any equipment for repair, call Keithley for technical
support at:
Monday - Friday, 8:00 a.m. - 5:00 p.m., Eastern Time
An applications engineer will help you diagnose and resolve your
problem over the telephone. Please make sure that you hav e the follo wing
information available before you call:
1-888-KEITHLEY
DAS-1200 Series Board
Configuration
Computer
7-6Troubleshooting
Model
Serial #
Revision code
Base address setting
Interrupt level setting
Number of channels
Input (S.E. or Diff.)
DMA chan(s)
Number of SSH-8 brds.
Number of EXP brds.
Gain selection setting
Manufacturer
CPU type
Clock speed (MHz)
KB of RAM
Video system
BIOS type
If a telephone resolution is not possible, the applications engineer will
issue you a Return Material Authorization (RMA) number and ask you to
return the equipment. Include the RMA number with any documentation
regarding the equipment.
7-7
When returning equipment for repair, include the following information:
●
Your name, address, and telephone number.
The invoice or order number and date of equipment purchase.
●
●
A description of the problem or its symptoms.
●
The RMA number on the
outside
of the package.
Repackage the equipment, using the original anti-static wrapping, if
possible, and handle it with ground protection. Ship the equipment to:
ATTN.: RMA# _______
Repair Department
Keithley Instruments, Inc.
28775 Aurora Road
Cleveland, Ohio 44139-1891
Telephone 1-888-KEITHLEY
FAX (440) 248-6168
Note:
If you are submitting your equipment for repair under warranty,
you must include the invoice number and date of purchase.
To enable Keithley to respond as quickly as possible, you must include
the RMA number on the outside of the package.
7-8Troubleshooting
Specifications
Tables A-1 to A-6 list specifications for the DAS-1200 Series boards.
Table A-1. Analog Input Specifications
AttributeDAS-1201 BoardsDAS-1202 Boards
Number of channelsSwitch-configurable as eight differential or 16 single-ended
Input mode bipolar
Resolution12-bits (1 part in 4096 or 244 ppm)
Gain (range)1 (±5.0 V) 1 (±5.0 V)
10 (±0.5 V) 2 (±2.5 V)
100 (±0.05 V)4 (±1.25 V)
A
500 (±0.01 V)8 (±0.625 V)
Gain (settling time)1 (22 µs)
10 (22 µs)
100 (22 µs)
500 (102 µs)
Throughput
Absolute accuracyTypical:
1
50 kHz maximum for gains less
than 500
10 kHz maximum for a gain of
500
0.01% of reading ±1 LSB, typical for all ranges after calibrating gain
and offset for that range
Maximum unadjusted error:
For gain < 500: 0.7% of reading ±1 LSB maximum @ 25˚C
For gain = 500: 0.8% of reading ±1 LSB maximum @ 25˚C
1 (10 µs)
2 (10 µs)
4 (10 µs)
8 (10 µs)
100 kHz maximum for all gains
A-1
Table A-1. Analog Input Specifications (cont.)
AttributeDAS-1201 BoardsDAS-1202 Boards
Temperature coefficient of
accuracy (includes ADC)
Gain:
±100 ppm/ ˚C maximum
Offset (referred to input):
(1 + 115/gain) µV/ ˚C maximum
Gain:
±150 ppm/ ˚C maximum
Offset (referred to input):
(10 + 200/gain) µV/ ˚C maximum
Conversion time: 8.5 µs maximum
Non-linearity ±1 LSB
Input impedanceGreater than 25 megohms
Input current250 nA maximum (125nA typ.) @ 25˚ C
Input bias current±2.0 nA maximum @ 25˚ C±0.002 nA maximum @ 25˚ C
±2.5 nA maximum over operating
range
±0.02 nA maximum over
operating range
Input overvoltage±35.0 V continuous powered
Common mode rejection
ratio
73 dB for gain = 173 dB for gain = 1
93 dB for gain = 1079 dB for gain = 2
110 dB for gain = 10084 dB for gain = 4
110 dB for gain = 50088 dB for gain = 8
2
Noise
Bipolar electrical noise (in
counts)
• Gain = 1: p-p = 1; rms = 0.1
• Gain = 10: p-p = 1; rms = 0.1
• Gain = 100: p-p = 2; rms = 0.2
• Gain = 500: p-p = 4; rms = 0.5
Bipolar electrical noise (in
counts)
• Gain = 1: p-p = 1; rms = 0.1
• Gain = 2: p-p = 1; rms = 0.1
• Gain = 4: p-p = 1; rms = 0.1
• Gain = 8: p-p = 2; rms = 0.2
DMA channels1 and 3
Interrupt levels2, 3, 4, 5, 6, and 7
A-2Specifications
Table A-1. Analog Input Specifications (cont.)
AttributeDAS-1201 BoardsDAS-1202 Boards
Minimum external pacer
10 ns
clock pulse width
Maximum external pacer
100 kHz
clock rate
Notes
1
Throughput is the maximum rate at which multiple channels can be scanned and still yield the same
result (within ±1 LSB) as a single channel scan (note that all channels must be within range of the
selected gain to assure proper settling). If using a single channel, the maximum sampling rate is
100 kHz for all gains.
2
The figures in the table show the electrical noise introduced by the analog front-end, but do not include
the uncertainty inherent in the quantization process. The inherent quantization noise introduced by any
ADC is due to uncertainty at code boundaries and adds a peak-to-peak value of 1 LSB to the electrical
noise; it also makes the rms level 0.5 LSBs.
Table A-2. Digital I/O Specifications (8-bits on Main I/O Connector)
AttributesDAS-1200 Series Boards
Outputs
(standard LSTTL)
Output bits: 4 bits latched
Low Voltage: 0.5 V maximum @ Isink= 8.0 mA
High voltage: 2.4 V minimum @ Isource = −0.4 mA
Inputs and interrupts
(standard LSTTL)
1
Input bits: 4
Low voltage: 0.8 V maximum
Low current: −0.2 mA maximum
High voltage: 2.0 V minimum
High current: 20 µA maximum
Notes
1
IP0/TRIG 0/XPCLK minimum pulse width = 10.0 ns.
A-3
Table A-3. Digital I/O Specifications (24-bits on PIO Cable Connector)
AttributesDAS-1200 Series Boards
Device typeNMOS 8255A-5
I/O24 bits
OutputsLow Voltage: 0.45 V maximum @ Isink = 1.7 mA
High voltage: 2.4 V minimum @ Isource = −0.2 mA
Inputs (and interrupts)Low voltage: 0.8 V maximum
Low current: −10 µA maximum
High voltage: 2.0 V minimum
High current: 10 µA maximum
Device type82C54-2
Number of counters3 down counters, 16-bit
2 permanently connected to 1/10 MHz
Outputs (buffered)Low voltage: 0.5 V maximum @ Isink = 25.0 mA
High voltage: 2.0 V minimum @ Isource = −15.0 mA
Inputs (buffered)Low voltage: 0.8 V maximum
Low current: −0.2 mA maximum
High voltage: 2.0 V minimum
High current: 20 µA maximum
Input and gateTTL/CMOS compatible
Clock inputDC to 10 MHz
Active count edgeNegative
Minimum clock pulse widths 30 ns high / 50 ns low
A-4Specifications
Table A-5. Power Supply Requirements
AttributeDAS-1200 Series Boards
+5 VDC supply235 mA typical
+12 VDC supply4 mA typical
−
12 VDC supply4 mA typical
Table A-6. Environmental Specifications
AttributeDAS-1200 Series Boards
Operating temperature0 to 70˚C
Storage temperature
Humidity0 to 95% noncondensing
Dimensions7 in. L × 4.25 in. H × 0.90 in. D
−
20 to 70˚C
(17.8 cm × 10.8 cm × 2.3 cm)
A-5
Connector Pin Assignments
This appendix contains pin assignments for the I/O connectors of the
DAS-1200 Series boards. See Figure 3-1 for the locations of connectors
discussed in this section.
Main I/O Connector (J1)
The pin assignments of the main I/O connector (J1) on the DAS-1200
Series boards are shown in Figure B-1.
B
Rear View
LL GNDPin 19
Ch0 LO IN / Ch8 HI INPin 18
Ch1 LO IN / Ch9 HI INPin 17
Ch2 LO IN / Ch10 HI INPin 16
Ch3 LO IN / Ch11 HI INPin 15
Ch4 LO IN / Ch12 HI INPin 14
Ch5 LO IN / Ch13 HI INPin 13
Ch6 LO IN / Ch14 HI INPin 12
Ch7 LO IN / Ch15 HI INPin 11
NOT CONNECTEDPin 10
NOT CONNECTEDPin 9
NOT CONNECTEDPin 8
POWER GNDPin 7
IP 1 / XTRIGPin 6
IP 3Pin 5
OP 1Pin 4
OP 3Pin 3
CTR 0 OUTPin 2
+5 V PWRPin 1
Pin 37Ch0 HI IN
Pin 36Ch1 HI IN
Pin 35Ch2 HI IN
Pin 34Ch3 HI IN
Pin 33Ch4 HI IN
Pin 32Ch5 HI IN
Pin 31Ch6 HI IN
Figure B-2. Pin Assignments of PIO Cable Connector (J4)
PORT A
PORT CH
PORT CL
B-2Connector Pin Assignments
Register-Level Address Map
DAS-1200 Series boards are programmable at the register -level using I/O
instructions. In BASIC, I/O instructions are
assembly and most other low-level languages, the I/O instructions are
similar to BASIC’s I/O instructions; for example, the assembly language
equivalents are
As an aid to register-level programming, this section describes each I/O
register in terms of function, address, bit structure, and bit functions. The
section does not describe how to program at the register-level.
Register Functions
IN AL,DX
and
OUT DX,AL
INP(X)
.
and
OUT X,Y
C
. In
DAS-1200 Series register functions are categorized as follows:
DAS-1200 Series boards use 32 I/O mapped addresses. The first 16
locations start at the base address in the computer’s I/O space. The next
eight locations start at the base address +400h. The remaining eight
locations are for future use; they have no current function.
The addresses start at the base address and extend as shown in the I/O
map of Table C-1.
Table C-1. Register-Level Address Map
LocationFunctionTypeName
Base Address +0hLow-byte of ADC register, A/D
conversion
Base Address +1hHigh-byte of ADC register ReadAD1
Base Address +2hADC MUX scan registerRead/WriteMUX
Base Address +3hDigital input byte (IP0-3), Board IDReadDIO
Digital output byte (OP0-3)Write
Base Address +4hNOT USED
Base Address +5hNOT USED
Base Address +6hNOT USED
Base Address +7hNOT USED
Base Address +8hStatus register ARead/WriteST ATUS A
Base Address +9hControl registerRead/WriteCTRL
Base Address +AhCounter enable and burst length register Read/WriteCNTEN
Base Address +Bh Burst rate registerRead/WriteGAIN
82C54 Programmable Interval Timer
Base Address +ChCounter 0 registerRead/WriteTIMER0
Read/WriteAD0
Base Address +DhCounter 1 registerRead/WriteTIMER1
Base Address +EhCounter 2 registerRead/WriteTIMER2
C-2Register-Level Address Map
Table C-1. Register-Level Address Map (cont.)
LocationFunctionTypeName
Base Address +Fh82C54 Counter ControlWriteTIMERCTL
Bidirectional digital ports A,B, CL, and CH (8255 Programmable I/O)
Base Address +400hDigital port ARead/WritePIOPA
Base Address +401hDigital port BRead/WritePIOPB
Base Address +402hDigital port CL and CHRead/WritePIOPC
Base Address +403h8255 control registerWritePIOCTL
Base Address +404hConversion disable registerWriteDISARM
Base Address +405hBurst mode enable registerWriteBMDEN
Base Address +406h1600 mode enable registerWrite1600MDEN
Base Address +407hStatus register BReadSTATUSB
The following sections describe the I/O registers in more detail.
ADC Registers (Base Address +0h and +1h)
Base address +0h and base address +1h are used for the following:
A/D conversion data
●
MUX channel number from which data is converted
●
●
Start a software controlled A/D conversion
The ADC registers are read in standard Intel 8088 Lo/Hi-byte sequence.
A write to base +0h initiates an A/D conversion.
C-3
Data is left-justified true binary, and the MUX channel address is in the
least-significant nibble; thus, data is tagged according to its channel of
origin. ADC data is latched so that data from the previous conversion is
available until the end of the following conversion. You can mask or
discard channel information, as required.
A write to base address +0h initiates an A/D conversion. An y data written
to these addresses is ignored.
Bit assignments of base address +0h are as follows:
76543210
CD3CD2CD1CD0MA3MA2MA1MA0
The bit names are defined and used as follows:
●
MA0 to MA3
●
CD0 to CD3
= Number of MUX channel converted.
= Four least significant bits of data converted from
MUX channel specified by MA0 to MA3.
Bit assignments of base address +1h are as follows:
76543210
CD11 CD10 CD9CD8CD7CD6CD5CD4
●
CD4 to CD11
= Eight most significant bits of data converted from
MUX channel specified by MA0 to MA3.
MUX Scan Register (Base Address +2h)
The MUX scan register is a read and write register that controls the
channel-scan limits of the ADC multiple x er. The high nibble provides the
end of scan address
The MUX scan register is set to 00h on power-up (reset).
C-4Register-Level Address Map
and the low nibble provides the
start of scan address
.
About 400 ns after the ADC multiplexer begins a conversion (and the
sample-and-hold is holding the previous channel) the multiplexer address
increments to be ready for the next conversion.
On finishing the conversion performed with the
cycle repeats starting with the
start of scan address
end of scan address
. On writing to the
, the
MUX scan register, the counter is automatically initialized to the start of
scan address.
To perform conversions on a single channel, the
scan addresses
should both be made equal to the target channel. If the
end of scan
and
start of
DAS-1200 Series board is to operate in 8-channel differential mode,
insure that the AH3 and AL3 bits are zero. The operating mode can
always be determined by reading bit 5 in status register A.
Bit assignments of base address +2h are as follows:
76543210
AH3AH2AH1AH0AL3AL2AL1AL0
The bit names are defined and used as follows:
●
AL0 to AL3
AH0 to AH3
●
= Start of scan address.
= End of scan address.
Unidirectional Digital Input and Output Registers
(Base Address +3h)
DAS-1200 Series unidirectional digital input and output consists of two
hardware-configured ports: a 4-bit latched output port (OP0 to 3) and a
4-bit input port (IP0 to 3).
These ports share the same I/O address but are independent; that is, data
written to the output port is not readable by the input port unless the OP0
to OP3 lines are externally connected to the IP0 to IP3 lines. The output
port is set to 0h on power-up (reset).
C-5
In addition, some input port lines perform secondary functions. IP0 is also
XPCLK and TRIG 0. XPCLK provides an external pacer clock to initiate
A/D conversions and TRIG 0 is used as a gate for the 82C54 counters one
and two. IP2 is also CTR 0 GATE, which controls operation of counter 0
in the 82C54 counter/timer.
Depending on your application, you may or may not use these secondary
functions. However, if you want to know the state of these inputs, read
base address +3h.
Bit assignments of base address +3h during a write are as follows:
76543210
XXXXOP3OP2OP1OP0
The bit names are defined and used as follows:
●
OP0 to OP3
X
= Data insensitive.
●
= Bits 0 to 3 of the digital output port.
Bit assignments of base address +3h during a read are as follows:
76543210
0010IP3IP2IP1IP0
The bit names are defined and used as follows:
●
IP0 to IP3
Bits 7 to 4
●
= Bits 0 to 3 of the digital input port.
= Board ID; these bits have a fixed value of 0010.
Status Register A (Base Address +8h)
Status register A is read only and provides information on the operation
and configuration of the DAS-1200 Series board. Writing to the status
register address clears the interrupt request.
C-6Register-Level Address Map
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