Acces I/O products RDAG12-8 User manual

ACCES I/O PRODUCTS INC
10623 Roselle Street, San Diego, CA 92121
TEL [phone] FAX [phone]
MODELS:
RDAG12-8,
RDAG12-8H,
U-RDAG12-8
U-RDAG12-8H
E-RDAG12-8
E-RDAG12-8H
S-RDAG12-8
S-RDAG12-8H
Analog Output Module
USER MANUAL
FILE: MRDAG12-8H.Bc2

Notice
The information in this document is provided for reference only. ACCES does not assume any liability
arising out of the application or use of the information or products described herein. This document may
contain or reference information and products protected by copyrights or patents and does not convey any
license under the patent rights of ACCES, nor the rights of others.
IBM PC,PC/XT, and PC/AT are registered trademarks of the International Business Machines Corporation.
Printed in USA. Copyright 2000 by ACCES I/O Products Inc, 10623 Roselle Street, San Diego, CA 92121.
All rights reserved.

Warranty
Prior to shipment, ACCES equipment is thoroughly inspected and tested to applicable specifications.
However, should equipment failure occur, ACCES assures its customers that prompt service and support
will be available. All equipment originally manufactured by ACCES which is found to be defective will be
repaired or replaced subject to the following considerations.
Terms and Conditions
If a unit is suspected of failure, contact ACCES' Customer Service department. Be prepared to give the unit
model number, serial number, and a description of the failure symptom(s). We may suggest some simple
tests to confirm the failure. We will assign a Return Material Authorization (RMA) number which must
appearontheouterlabelofthereturnpackage. Allunits/componentsshould beproperlypackedforhandling
and returned with freight prepaid to the ACCES designated Service Center, and will be returned to the
customer's/user's site freight prepaid and invoiced.
Coverage
First Three Years: Returned unit/part will be repaired and/or replaced at ACCES option with no charge for
labor or parts not excluded by warranty. Warranty commences with equipment shipment.
Following Years: Throughout your equipment's lifetime, ACCES stands ready to provide on-site or in-plant
service at reasonable rates similar to those of other manufacturers in the industry.
Equipment Not Manufactured by ACCES
Equipment provided but not manufactured by ACCES is warranted and will be repaired according to the
terms and conditions of the respective equipment manufacturer's warranty.
General
Under this Warranty, liability of ACCES is limited to replacing, repairing or issuing credit (at ACCES
discretion) for any products which are proved to be defective during the warranty period. In no case is
ACCES liable for consequential or special damage arriving from use or misuse of our product. The
customer is responsible for all charges caused by modifications or additions to ACCES equipment not
approved in writing byACCES or,if in ACCES opinion the equipment has been subjected to abnormal use.
"Abnormal use" for purposes of this warranty is defined as any use to which the equipment is exposed other
than that use specified or intended as evidenced by purchase or sales representation. Other than the above,
no other warranty, expressed or implied, shall apply to any and all such equipment furnished or sold by
ACCES.
Page iii

Table of Contents
Chapter1: Introduction...............................................1-1
Description............................................................ 1-1
Specifications.......................................................... 1-3
Chapter2: Installation...............................................2-1
CDInstallation.......................................................... 2-1
Directories Created on the Hard Disk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
GettingStarted......................................................... 2-3
Calibration............................................................. 2-6
Installation............................................................. 2-6
Input/OutputPinConnections.............................................. 2-6
Chapter3: Software..................................................3-1
General............................................................... 3-1
CommandStructure..................................................... 3-1
CommandFunctions..................................................... 3-3
ErrorCodes........................................................... 3-10
Appendix A: Application Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Introduction............................................................A-1
BalancedDifferentialSignals...............................................A-1
RS485DataTransmission. ...............................................A-3
Appendix B: Thermal Considerations.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
Page iv

List of Figures
Figure 1-1: RDAG12-8 Block Diagram.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 1-6
Figure 1-2: RDAG12-8 Hole Spacing Diagram.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 1-7
Figure 2-1: Simplified Schematic for Voltage and Current Sink Outputs . . . . . . . . . . . Page 2-9
Figure A-1: Typical RS485 Two-Wire Multidrop Network. . . . . . . . . . . . . . . . . . . . . . . Page A-3
List of Tables
Table 2-1: 50 Pin Connector Assignments.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2-7
Table 3-1: RDAG12-8 Command List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 3-2
Table A-1: Connections Between Two RS422 Devices.. . . . . . . . . . . . . . . . . . . . . . . . Page A-1
Table A-2: RS422 Specification Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page A-2
Page v

Chapter 1: Introduction
Features
• Remote Intelligent Analog Output and Digital I/O Units with Opto-Isolated RS485 Serial
Interface to Host Computer
• Eight 12-Bit Analog Current Sinks (4-20mA) and Voltage Outputs
• Software Selectable Voltage Ranges of 0-5V, 0-10V, ±5V
•Low-Power and High-Power Analog Output Models
•Seven Bits of Digital I/O Configured on a Bit-by-Bit Basis as either Inputs or High-
Current Outputs
•Field Connections Accomplished via 50-pin Removable Screw Terminals
•Onboard 16-bit 8031 Compatible Microcontroller
• All Programming and Calibration in Software, No Switches to Set. Jumpers Available to
By-Pass Opto-Isolators if Desired
• Protective Metal T-Box included
Description
RDAG12-8 is an intelligent, 8-channel, digital-to-analog converter unit that communicates with the
host computer via EIA RS-485, Half-Duplex, serial communications standard. ASCII-based
command/response protocol permits communication with virtually any computer system.
RDAG12-8 is one of a series of remote intelligent Pods called the "REMOTE ACCES Series". As
many as 32 REMOTE ACCES Series Pods (or other RS485 devices) may be connected on a single
two or four-wire multidrop RS485 network. RS485 repeaters may be used to extend the number of
Pods on a network. Each unit has a unique address. Communication uses a master/slave protocol
wherein the Pod talks only if questioned by the computer.
An 80C310 Dallas microcontroller (with 32k x 8 bits RAM, 32K bits non-volatile EEPROM, and
a watchdog timer circuit) gives RDAG12-8 the capability and versatility expected from a modern
distributed control system. RDAG12-8 contains CMOS low-power circuitry, an optically-isolated
receiver/transmitter, and power conditioners for local and external isolated power. It can operate
at baud rates up to 57.6 Kbaud and distances up to 4000 feet with low-attenuation twisted-pair
cabling, such as Belden #9841 or equivalent. Data collected by the Pod can be stored in local RAM
and accessed later through the computer's serial port. This facilitates a stand-alone Pod mode of
operation.
AllprogrammingofRDAG12-8isinASCII-basedsoftware. ASCII-basedprogrammingpermitsyou
to write applications in any high-level language that supports ASCII string functions.
The module, or Pod, address is programmable from 00 to FF hex and whatever address is assigned
is stored in EEPROM and used as the default address at the next Power-ON.Similarly, the baud rate
is programmable for 1200, 2400, 4800, 9600, 14400, 19200, 28800, and 57600. The baud rate is
stored in EEPROM and used as default at the next Power-ON.
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Analog Outputs
These units consist of eight independent 12-bit digital-to-analog converters (DACs), and amplifiers
for voltage outputs and voltage-to-current conversion. The DACs may be updated in a channel-by-
channel mode or simultaneously. There are eight channels of voltage output and eight
complimentary channels for 4-20mA current output sinks. The output voltage ranges are software
selectable. Calibration is performed by software. Factory calibration constants are stored in the
EEPROM memory and can be updated by disconnecting the I/O wiring and entering the software
calibration mode. Model RDAG12-8 can supply analog outputs of up to 5 mA on voltage ranges of
0-5V, ±5V, and 0-10V. By writing discrete values of a desired waveform into the buffers and
loading the buffers into the DAC at a programmable rate (31-6,000Hz) the units can generate
arbitrary waveforms or control signals.
Model RDAG12-8H is similar except that each DAC output can drive loads up to 250mA using a
±12V @ 2.5A local power supply.
Digital I/O
Both models also have seven digital input/output ports. Each port can be individually programmed
as an input or an output. Digital input ports can accept logic high input voltages up to 50V and are
overvoltage protected to 200 VDC. Output drivers are open collector and can comply with up to 50
VDC of user-supplied voltage. Each output port can sink up to 350 mA but total sink current is
limited to a cumulative total of 650 mA for all seven bits.
Watchdog Timer
The built-in watchdog timer resets the Pod if the microcontroller "hangs up" or the power supply
voltage drops below 7.5 VDC. The microcontroller may also be reset by an external manual
pushbutton connected to /PBRST (pin 41 of the interface connector).
Page 1-2 Manual MRDAG12-8H.Bc2

Specifications
Serial Communications Interface
• Serial Port: Opto-isolated Matlabs type LTC491 Transmitter/Receiver. Compatible
with RS485 specification. Up to 32 drivers and receivers allowed on the
line. I/O bus programmable from 00 to FF hex (0 to 255 decimal).
Whatever address is assigned is stored in EEPROM and used as default
at next Power-On.
• Asynchronous Data Format: 7 data bits, even parity, one stop bit.
• Input Common Mode Voltage: 300V minimum (opto-isolated). If opto-isolators are
by-passed: -7V to +12V.
• Receiver Input Sensitivity: ±200 mV, differential input.
• Receiver Input Impedance: 12KΩminimum.
• Transmitter Output Drive: 60 mA, 100 mA short circuit current capability.
• Serial Data Rates: Programmable for 1200, 2400, 4800, 9600, 14400, 19200,
28800, and 57600 baud. Crystal oscillator provided.
Analog Outputs
• Channels: Eight independent.
• Type: 12-bit, double-buffered.
• Non-Linearity: ±0.9 LSB maximum.
• Monotonicity: ±½ bit.
• Output Range: 0-5V, ±5V, 0-10V.
• Output Drive: Low Power Option: 5 mA, High Power Option: 250 mA.
• Current Output: 4-20 mA SINK (User supplied excitation of 5.5V-30V).
• Output Resistance: 0.5.
• Settling Time: 15 µsec to ±½ LSB.
Digital I/O
• Seven bits configured as input or output.
• Digital Inputs Logic High: +2.0V to +5.0V at 20µA max. (5mA max at 50V in)
Protected to 200 VDC
Logic Low: -0.5V to +0.8V at 0.4 mA max. Protected to -140 VDC.
• Digital Outputs Logic-Low Sink Current: 350 mA maximum. (See note below.)
Inductive kick suppression diode included in each circuit.
Note
Maximum allowable current per output bit is 350 mA. When all seven bits are used, there is a
maximum total current of 650 mA.
• High-Level Output Voltage: Open Collector, compliance with up to 50VDC
user-supplied voltage. If no user supplied voltage exists,
outputs pulled up to +5VDC via 10 kΩresistors.
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RDAG12-8 Manual
Interrupt Input (For use with development kit)
• Input Low: -0.3V to +0.8V.
• Input Low Current at 0.45V: -55µA.
• Input High: 2.0V to 5.0V.
Environmental
The environmental characteristics depend on the RDAG12-8 configuration.
Low and High power output configurations:
• Operating Temperature Range: 0 EC. to 65 EC. (Optional -40 EC. to +80 EC.).
• Temperature De-rating: Based on the power applied, maximum operating
temperature may have to be de-rated because internal
power regulators dissipate some heat. For example,
when 7.5VDC is applied, the temperature rise inside the
enclosure is 7.3EC above the ambient temperature.
Note
Maximum operating temperature can be determined according to the following equation:
I(TJ = 120) A
V < 22.5 - 0.2T
A I(TJ = 120)
Where T is the ambient temperature in EC. and V is the voltage at which the integral voltage
regulator junction temperature will rise to a temperature of 120 EC.
(Note: The junction temperature is rated to 150 EC. maximum.)
I
For example, at an ambient temperature of 25 EC., the voltage V can be up to 17.5V.
I
At an ambient temperature of 100 EF. (37.8 EC.), the voltage V can be up to 14.9V.
• Humidity: 5% to 95% RH non-condensing.
Page 1-4 Manual MRDAG12-8H.Bc2

Power Required
Power can be applied from the computer's +12VDC power supply for the opto-isolated section
via the serial communication cable and from a local power supply for the rest of the unit. If you do not
wish to use power from the computer, a separate power supply isolated from the local power supply may
be used for the opto-isolated section. The power used by this section is minimal (less than 0.5W).
Low power version:
• Local Power: +12 to 18 VDC @ 200 mA. (See box that follows.)
• Opto-Isolated Section: 7.5 to 25 VDC @ 40 mA. (Note: Due to the small amount of
current required, voltage drop in long cables is not significant.)
High power version:
• Local Power: +12 to 18 VDC at up to 2 ½ A, and -12 to -18V at 2A depending
on the output load drawn.
• Opto-Isolated Section: 7.5 to 25 VDC @ 50 mA. (Note: Due to the small amount of
current required, voltage drop in long cables is not significant.)
Note
If the local power supply has an output voltage greater than 18VDC, you can install a Zener diode
Z
in series with the supply voltage. The voltage rating of the Zener diode (V ) should be equal to
I I
V -18 where V is the power supply voltage. The power rating of the Zener diode should be $
Z
V x0.12 (watts). Thus, for example, a 26VDC power supply would require using an 8.2V Zener
diode with a power rating of 8.2 x 0.12 .1 watt.
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Figure 1-1: RDAG12-8 Block Diagram
Page 1-6 Manual MRDAG12-8H.Bc2

Figure 1-2: RDAG12-8 Hole Spacing Diagram
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Manual MRDAG12-8H.Bc2

Chapter 2: Installation
The software provided with this card is contained on CD and must be installed onto your hard disk
prior to use. To do this, performthe followingsteps applicable for youroperatingsystem. Substitute
the appropriate drive letter for your CD-ROM where you see d: in the examples below.
CD Installation
WIN95/98/NT/2000
a. Place the CD into your CD-ROM drive.
b. The install program should automatically run after 30 seconds. If the install program does
not run, click START | RUN and type d:install, click OK or press K.
c. Follow the on-screen prompts to install the software for this card.
Directories Created on the Hard Disk
The installation process will create several directories on your hard disk. If you accept the
installation defaults, the following structure will exist.
[CARDNAME]
Root or base directory containing the SETUP.EXE setup program used to help you configure
jumpers and calibrate the card.
DOS\PSAMPLES: A subdirectory of [CARDNAME] that contains Pascal samples.
DOS\CSAMPLES: A subdirectory of [CARDNAME] that contains "C" samples.
Win32\language: Subdirectories containing samples for Win95/98 and NT.
WinRISC.exe
A Windows dumb-terminal type communication program designed for RS422/485 operation.
Used primarily with Remote Data Acquisition Pods and our RS422/485 serial communication
product line. Can be used to say hello to an installed modem.
ACCES32
This directory contains the Windows 95/98/NT driver used to provide access to the hardware
registers when writing 32-bit Windows software. Several samples are provided in a variety of
languages to demonstrate how to use this driver. The DLL provides four functions (InPortB,
OutPortB, InPort, and OutPort) to access the hardware.
This directoryalsocontains the devicedriverfor WindowsNT,ACCESNT.SYS. Thisdevicedriver
provides register-level hardware access in Windows NT. Two methods of using the driver are
available, through ACCES32.DLL (recommended) and through the DeviceIOControl handles
provided by ACCESNT.SYS (slightly faster).
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SAMPLES
Samples for using ACCES32.DLL are provided in this directory. Using this DLL not only
makes the hardware programming easier (MUCH easier), but also one source file can be used
for both Windows 95/98 and WindowsNT. One executable can run under both operating
systems and still have full access to the hardware registers. The DLL is used exactly like any
other DLL, so it is compatible with any language capable of using 32-bit DLLs. Consult the
manuals provided with yourlanguage'scompiler for information on using DLLs in your specific
environment.
VBACCES
This directory contains sixteen-bit DLL drivers for use with VisualBASIC 3.0 and Windows 3.1
only. These drivers provide four functions, similar to the ACCES32.DLL. However, this DLL is
only compatible with 16-bit executables. Migration from 16-bit to 32-bit is simplified because of
the similarity between VBACCES and ACCES32.
PCIThis directory contains PCI-bus specific programs and information. Ifyou are not using a PCIcard,
this directory will not be installed.
SOURCE
A utility program is provided with source code you can use to determine allocated resources at
run-time from your own programs in DOS.
PCIFind.exe
A utility for DOS and Windows to determine what base addresses and IRQs are allocated to
installed PCI cards. This program runs two versions, depending on the operating system. Windows
95/98/NT displays a GUIinterface, and modifies the registry. When run from DOS or Windows3.x,
a text interface is used. For information about the format of the registry key, consult the
card-specific samples provided with the hardware. In Windows NT, NTioPCI.SYS runs each time
the computer is booted, thereby refreshing the registry as PCI hardware is added or removed. In
Windows 95/98/NT PCIFind.EXE places itself inthe boot-sequence of the OSto refresh the registry
on each power-up.
This programalso providessomeCOMconfiguration when usedwithPCICOMports. Specifically,
it will configure compatible COM cards for IRQ sharing and multiple port issues.
WIN32IRQ
This directory provides a generic interface for IRQ handling in Windows 95/98/NT. Source code
is provided for the driver, greatly simplifying the creation of custom drivers for specific needs.
Samples are provided to demonstrate the use of the generic driver. Note that the use of IRQs in
near-real-time data acquisition programs requires multi-threaded application programming
techniques and must be considered an intermediate to advanced programming topic. Delphi, C++
Builder, and Visual C++ samples are provided.
Page 2-2 Manual MRDAG12-8H.Bc2

Findbase.exe
DOS utility to determine an available base address for ISA bus , non-Plug-n-Play cards. Run this
program once, before the hardware is installed in the computer, to determine an available address
to give the card. Once the address has been determined, run the setup program provided with the
hardware to see instructions on setting the address switch and various option selections.
Poly.exe
A generic utility to convert a table of data into an nth order polynomial. Useful for calculating
linearization polynomial coefficients for thermocouples and other non-linear sensors.
Risc.bat
A batch file demonstrating the command line parameters of RISCTerm.exe.
RISCTerm.exe
A dumb-terminal type communication program designed for RS422/485 operation. Used primarily
with Remote Data Acquisition Pods and our RS422/485 serial communication product line. Can be
used to say hello to an installed modem. RISCTerm stands for Really Incredibly Simple
Communications TERMinal.
Getting Started
To begin working with the pod, you first need an available working serial communications port on
your PC. This can be either one of our RS422/485 Serial Communication cards or an existing RS-
232portwitha232/485two-wireconverterattached.Next,installthesoftwarefromthe3½" diskette
(RDAG12-8 Software Package). You should also run the RDAG12-8 setup program (which is on
the 3½" diskette) to help you with option selection.
1. Verify that you are able to communicate through the COM port (see details in the appropriate COM
card manual). View Control Panel | Ports (NT 4) or Control Panel | System| DeviceManager |Ports
| Properties | Resources (9x/NT 2000) for information about installed COM ports. Communication
verification can be done by using a loop-back connector with the card in full-duplex RS-422 mode.
A working knowledge of serial ports in Windows will significantly contribute to your success. You
may have built-in COM ports 1 & 2 on your Motherboard, but the software necessary to support
them may not be installed in your system. From the Control Panel you may need to “add new
hardware” and select standard serial communication port to add a COM port to your system. You
may also need to check in the BIOS to ensure that the two standard serial ports are enabled.
We provide two terminal programs to aid with this task. RISCTerm is a DOS-based terminal
program, which can also be used in Windows 3.x and 9x. For Windows 9x/NT 4/NT 2000, you can
use our WinRISC program. You can select the COM port number (COM5, COM8, etc.), baud, data
bits, parity, and stop bits. ACCES Pods ship at 9600, 7, E, 1, respectively. The simplest test to see
if you have a good COM port without connecting anything to the COM Port connector on the back
of your computer is to select either COM 1 or COM 2 (whichever one is showing up in your device
manager) from WinRISC(See “RunningWinRISC”) then clicking on “Connect”. If youdon’t get
an error, that is a very good sign that you’re in business. Click the checkbox called “local echo”,
then click into the text window, where you should see theblinking cursor, and start typing. If you’ve
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succeeded in getting to the last step, you’re ready to connect the hardware and attempt to
communicate with it.
2. After you have verified that you are able to communicate through your COM port, set up your COM
card for half-duplex, RS-485, and wire it up using two wires to the Pod. (You may need to move
some jumpers on the COM board to accomplish this. Or if you’re using our RS-232/485 Converter,
please connect it at this time. Communication with the Pod should be two-wire RS-485, Half-
Duplex with Termination and Bias applied. Also select No Echo (where Echo exists) on the COM
card. See your manual for the COM card for further details.) You also have to wire appropriate
power to the Pod terminals. See the Screw Terminal Pin assignments for help with this. For best
results, you’ll need +12V and a return to power the pod in the non-isolated mode. For bench testing
and setup with one power supply, you’ll need to install wire jumpers between the following
terminals on the terminal block: ISOV+ to PWR+, and ISOGND to GND. This defeats the optical
isolation feature of the Pod, but eases the development setup and only requires one power supply.
You should also check the processor board as described in Option Selection to ensure the jumpers
JP2, JP3 and JP4 are in the /ISO position.
3. Verify your wiring, then turn on power to the Pod. If you’re checking, the current draw should be
approximately 250mA.
4. Now you can again run the setup and calibration program(DOS, Win3.x/9x). This time the setup
program should auto-detect the Pod from the auto-detect menu item, and allow you to run the
calibration routine. If you’re using Windows NT, you can run the setup program to set the jumpers
regarding isolated or non-isolated communication. To run the calibration routine, just use a DOS
boot disk, then run the program. We can provide this if necessary.
Running WinRISC
1. For Windows 9x/NT 4/NT 2000, start the WinRISC program, which should be accessible from the
start menu (Start | Programs | RDAG12-8 | WinRISC). If you can’t find it, go to Start | Find | Files
or Folders and search for WinRISC. You can also explore the CD and look for
disks\tools.win\Win32\WinRISC.exe.
2. Once you’rein WinRISC,select a baud rate of 9600 (factory default for the Pod). Select Local Echo
and the following other settings: Parity-Even, Data Bits-7, Stop Bits-1. Leave other settings at the
default. Select the verified COM port (top left) and click on “Connect”.
3. Click into the main box. You should see a blinking cursor.
4. Type a few characters. You should see them print to the screen.
5. Proceed to the section “TALKING TO THE POD”.
Page 2-4 Manual MRDAG12-8H.Bc2

Running RISCterm
1. For Win 95/98, run the program RISCTerm.exe found in Start | Programs | RDAG12-8. For DOS
or Win 3.x, look in C:\RDAG12-8.
2. Enter the base address of the COM card, then enter the IRQ. In Windows, this information is
available by viewing the ControlPanel | System | DeviceManager | Ports | Properties | Resources.
3. Once you’re in RISCTerm, verify a selection of 9600 baud (factory default for the Pod). The bar
across the bottom of the screen should say 7E1.
4. Type a few letter characters. You should see them print to the screen.
5. Proceed to the section, “TALKING TO THE POD”.
Talking to the Pod
1. (Pickingupfromstep5of“RUNNINGWINRISC”or“RUNNINGRISCTERM”)Press the Enter
keyafewtimes. Youshouldreceive,“Error,use ?forcommandlist,unrecognizedcommand:” This
is your first indication that you’re talking to the Pod. Repeatedly pressing the Enter key should
return this message each time. This is a correct indication.
2. Type “?” and press enter. You should receive back “Main Help Screen” and three possible other
menus to access. You could type “?3" then press Enter, and receive a menu back from the Pod
regarding Analog Output Commands. If you’re receiving these messages, you again know that you
are communicating effectively with the Pod.
3. Connect a DMM, set for 20VDC range, across pins 1(+) and2 (-) ofthe Pod’s screw terminal block.
Type “AC0=0000,00,00,01,0000" and [Enter]. You should receive a CR (carriage return) from the
Pod. This command sets Channel 0 for the 0-10V range.
4. Now type “A0=FFF0" and [Enter]. You should receive a carriage return from the Pod. This
command causes Channel 0 to output the commanded value (FFF in hex = 4096 counts, or 12-bit,
Full Scale). You should see the DMM read 10VDC. Calibration is discussed in the following
section.
5. Type “A0=8000” and [Enter] (800 in hex = 2048 counts, or 12-bit, Half Scale). You should receive
a carriage return from the Pod. You should see the DMM read 5VDC.
6. You’re now ready to begin your development and write your application program.
Note: If you’re ultimately going to use the “Isolated Mode”, be sure that you put the
jumpers on the processor board back to the “ISO” positions. Also ensure that you
wire the power up correctly to support that mode. It requires 12V of local power,
and 12V of isolated power. Isolated Power can be supplied from the computer’s
power supply, or some other central supply. Current draw on this source is
negligible, so voltage drop in the cable is of no consequence. Be aware that the High
Power Pod version (RDAG12-8H) requires +12V, Gnd, and -12V for “Local Power”.
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Calibration
The setup software provided with the RDAG12-8 and RDAG12-8H supports the ability to check
calibration and to write correction values into EEPROM so they are available automatically on
power-up. Calibration checks need only be performed periodically, not every time power is cycled.
The SETUP.EXE software calibration procedure can be used to calibrate all three ranges and store
the values in the EEPROM. For Windows NT, you’ll need to boot to DOS to run this program. You
can create a DOS boot disk from any Windows system not runningNT. We canprovide a DOSboot
disk if necessary.
The SAMPLE1 program illustrates the procedure of recalling these values and adjusting the
readings. The description of the CALn? command shows the order in which the information is
stored in the EEPROM.
Installation
TheRDAG12-8andthe RDAG12-8Henclosureisanon-sealedsteelenclosurewithapowdercoated
finish. The enclosure measures 8" long by 5.32" wide by 2.2" high.
There are three jumper locations on the unit and their functions are as follows:
JP2, JP3, and JP4: Normally these jumpers should be in the "ISL" position. If you wish to
by-pass the opto-isolators, then you can move these jumpers to the "/ISL"
position.
Input/Output Pin Connections
Electrical connections to the RDAG12-8 are through cutouts in the ends of the enclosure.
Some versions of this product terminate in 2 DB25 connectors, see enclosure label for pinout.
Connector pin assignments for the 50-pin connector follow:
Page 2-6 Manual MRDAG12-8H.Bc2

Pin Signal Pin Signal
1 VOUT0 (Analog Volt. Output 0) 2 APG0 (Analog Power Ground 0)
3 VOUT1 (Analog Volt. Output 1) 4 APG1 (Analog Power Ground 1)
5 VOUT2 (Analog Volt. Output 2) 6 APG2 (Analog Power Ground 2)
7 GND (Local Power Ground) 8 DIO6 (Digital Input/Output 6)
9DIO5 (Digital Input/Output 5) 10 DIO4 (Digital Input/Output 4)
11 DIO3 (Digital Input/Output 3) 12 DIO2 (Digital Input/Output 2)
13 DIO1 (Digital Input/Output 1) 14 DIO0 (Digital Input/Output 0)
15 GND (Local Power Ground) 16 APG3 (Analog Power Ground 3)
17 VOUT3 (Analog Volt. Output 3) 18 IOUT0 (Analog Current Output 0)
19 IOUT1 (Analog Current Output 1) 20 IOUT2 (Analog Current Output 2)
21 IOUT3 (Analog Current Output 3) 22 AOGND (Analog Output Ground)
23 IOUT4 (Analog Current Output 4) 24 IOUT5 (Analog Current Output 5)
25 IOUT6 (Analog Current Output 6) 26 IOUT7 (Analog Current Output 7)
27 AOGND (Analog Output Ground) 28 APG4 (Analog Power Ground 4)
29 VOUT4 (Analog Volt. Output 4) 30 AOGND (Analog Output Ground)
31 GND (Local Power Ground) 32 N/A
33 N/A 34 PWR- (Local Power Supply-)
35 PWR+ (Local Power Supply +) 36 PWR+ (Local Power Supply +)
37 GND (Local Power Ground) 38 APG5 (Analog Power Ground 5)
39 VOUT5 (Analog Volt. Output 5) 40 PWR- (Local Power Supply -)
41 /PBRST (Pushbutton Reset) 42 ISOGND (Isol. Power Supply)
43 ISOV+ (Isol. Power Supply +) 44 RS485+ (Communication Port +)
45 /RS485- (Communication Port -) 46 APG6 (Analog Power Ground 6)
47 VOUT6 (Analog Volt. Output 6) 48 APPLV+ (Digital Out Application Pwr.)
49 VOUT7 (Analog Volt. Output 7) 50 APG7 (Analog Power Ground 7)
Table 2-1: 50 Pin Connector Assignments
Terminal markings and their functions are as follows:
PWR+ and GND: (Pins 7, 15, 31, 35, and 37) These terminals are used to apply local power
to the Pod from a local power supply. (Pins 35 and 36 are tied together.)
The voltage can be anywhere in the range of 12 VDC to 18 VDC. Higher
voltage can be used, 24 VDC for example, if an external Zener diode is
used to reduce the voltage applied to the RDAG12-8. (See the
Specification section of this manual to determine the Zener diode power
rating required.)
PWR- (Pin 40) This terminal accepts customer supplied -12V to -18 VDC @ 2A
max. It is used only in the High Power option RDAG12-8H.
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Manual MRDAG12-8H.Bc2

RDAG12-8 Manual
ISOV+ and ISOGND: This is the power connection for the isolator section that may be supplied
from the computer's +12VDC supply via a pair of wires on the RS-485
network or from a central power supply. This power is independent of
"local power". The voltage level can be from 7.5 VDC to 35 VDC. (An
on-board voltage regulator regulates the power to +5 VDC.) RDAG12-8
will require only about 5 mA of current when idling and ~33mA current
when data is being transmitted so any loading effects on the computer
power (if used) will be low.
Note
If separate power is not available, ISOV+ and ISOGND must be jumpered to the "local power"
terminals, which defeats the optical isolation.
RS485+ and RS485-: These are the terminals for RS485 communications (TRx+ and TRx-).
APPLV+: This terminal is a single common pin for the cathodes of the inductive
suppression diodes included in the 7 Digital Outputs. If a Digital Output is
controlling aRelay coil asuppression diode (aka flyback diode) is required
to limit the voltage spike at the output pin when the Relay coil is turned off.
If different Relay coil voltages are controlled at the Digital outputs then
only the highest voltage can be connected to the APPLV+ pin.
APG0-7: These terminals are for use with the High Power version of the Pod
(RDAG12-8H). Connect all load returns to these terminals.
AOGND: These terminals are for use with the Low Power version of the Pod. Use
these for returns of voltage outputs as well as current outputs.
GND: These are general purpose grounds which can be used for Digital Bit
returns, Power return connections, and so on.
To ensure that there is minimum susceptibility to EMI and minimum radiation, it is important that
there be a positive chassis ground. Also, proper EMI cabling techniques (cable connected to chassis
ground, twisted pair wiring, and, in extreme cases, ferrite-level of EMI protection) may be needed
for input/output wiring.
VOUT0-7: Analog Output Voltage signal, use in conjunction with AOGND
IOUT0-7: 4-20mA Current Sink Output signal, use in conjunction with an external
power supply (5.5V to 30V).
Page 2-8 Manual MRDAG12-8H.Bc2