System 50
CONTROLLERS
MicroDAC LT (Optomux)
FEATURES
• Each Unit Controls/Monitors up to
32 Analog (G5 Only) and/or Digital
I/O Modules
• Executes On-Board Programs
Created With Borland C
• Network up to 64 MicroDAC LTs
per Host Serial Port, Spanning as
Much as 4000 Feet
• Communicate Over RS-422 /485 at
Speeds From 1200 Baud to
115.2 KB
• 100% Optomux Compatible, With
Expanded Command Set
• I/O Update Rates of 500 µSec per
32 Digital I/O, and 10 mS per
Analog Input or 2 Analog Outputs
• 64-Bit Floating Point Math
APPLICATIONS
and control the outputs. In addition to simple
ON/OFF instructions, commands are included
which permit you to:
• Sample analog signals at 10 mS per input
• Flag values above or below prescribed levels
• Capture min/max values
• Calculate the average input signal levels
• Provide linearized thermocouple and
RTD temperature values
• Determine the width of input pulses
• Count pulses at frequencies up to 1000Hz
• Detect rising or falling edges
• Latch momentary input events
• Set the level of analog outputs
• Provide delayed-on or delayed-off outputs
Even while an Embedded Control Program
(ECP) is running on MicroDAC LT, any
Optomux
™
command it receives from the host
will be processed as usual, which allows you to
delegate some or all of the control and data
acquisition responsibility from the host computer.
This reduces communications time and
improves system response.
For embedded or stand-alone applications,
downloaded ECP routines can be initiated on
power-up.
Libraries and the appropriate download utility
are included with the ECP Programmers
Manual.
GENERAL DESCRIPTION
MicroDAC LT is a low cost version of MicroDAC
for customers who don't need all of the features
of MicroDAC. Missing are the battery back-up
for the RAM memory, real-time clock, RS-232,
and SBX ports. The DIN Rail Mountable metal
enclosure is optional. ECP routines written for
MicroDAC can be easily transferred to
MicroDAC LT and vice versa. By combining
MicroDAC, MicroDAC LT and ProMux the
cost/performance of a distributed control or
data acquisition network is optimized for price
and performance.
System 50
COMMUNICATIONS
The host computer and MicroDAC LT(s)
communicate serially over one or two pair of
twisted wires per RS-422/485 in a multi-drop
configuration. They use Optomux
™
ASCII
format to code the command and the response
messages. Application programs running on
the host computer issue commands and then
await responses from the MicroDAC. The
communications speed is selectable between
1.2 and 115.2 KBaud. Each controller on the
network is assigned a unique base address.
The entire network can span 4000 feet.
SOFTWARE
Software drivers are available which simplify
the task of interfacing host programs written in.
Visual Basic or C to the MicroDAC network.
Sample programs, set-up and debug utilities
are included on the disk with the drivers.
Interface drivers for most third party software
packages are available through their
distributors. Our MicroDAC DDE Server
dramatically simplifies data sharing between
MicroDACs and Windows applications, such
as Microsoft Excel (see Controller Software).
Our DLL will assist you in building custom
Windows Man-Machine Interfaces or control
programs using Visual Basic, Visual C/C
++
, or
Borland compilers.
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ANALOG & DIGITAL I/O
MicroDAC LT connects directly to any 8,16,24,
or 32 module mounting rack with a 50-pin
header. If connected to a G5 rack, any
combination of analog and digital I/O modules
may be used. Standard and Mini racks permit
only a combination of digital modules. MicroDAC
LTs can be networked to a host PC which
execute programs that monitor the input signals
EMBEDDED CONTROL PROGRAMS
By specifying MicroDAC LT(s) with the optional
64KB of flash memory, you can develop and
download C language programs to any of the
networked controllers.
With optional enclosure.
System 50
Grayhill, Inc. • 561 Hillgrove Avenue • LaGrange, Illinois 60525-5997 • USA • Phone: 708-354-1040 • Fax: 708-354-2820 • www.grayhill.com
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GRAYHILL [ GRAYHILL, INC ]
