70M-OSW1 Grayhill, Inc, 70M-OSW1 Datasheet - Page 5

• Manufacturer Part Number: 70M-OSW1
• Description: Opendac I/o System Low Cost Remote I/o System
• Manufacturer: Grayhill, Inc

OpenDAC
APPLICATIONS
• Communicate Over RS-422/485 at
• 100% Modbus ASCII or Modbus
• CE Certified
NETWORK INTERFACES
OpenDAC
FEATURES
• Each Unit Controls/Monitors up to
• Network up to 247 OpenDACs
• DIN Rail or Panel Mount
32 Analog and/or Digital I/O using
OpenLine
Host PC, Each Separated by as
much as 4,000 Feet
Speeds from 9600 Baud to 56.7 KB
RTU Compatible
4
Grayhill, Inc. • 561 Hillgrove Avenue • LaGrange, Illinois 60525-5997 • USA • Phone: [phone] • Fax: [phone] • www.grayhill.com
Stand Alone Control
Local Control & I/O
®
Distributed I/O
®
Modules
Remote I/O
for Modbus
SCADA
RTU
OpenDAC
®
®
per
I/O System
GENERAL DESCRIPTION
OpenDAC
flexible interface to 32 analog or digital
OpenLine
a Modbus network, OpenDAC
constantly scans and stores the current status
of each I/O. Upon command from the host
device, the controller will change the status of
an output or return the value of an input. The
slave address is switch selectable. Diagnostic
LEDs provide troubleshooting assistance.
ANALOG & DIGITAL I/O
OpenDAC
16 channel racks. Any combination of analog
and digital I/O modules may be used. On power
up, the OpenDAC
configuration and makes the information
available to the master for query.
In addition to simple On/Off instructions, Modbus
commands allow you to:
• Read linearized thermocouple and RTD
• Count pulses at frequencies up to 1000Hz
• Detect rising or falling edges
• Latch momentary input events
• Set the level of analog outputs
COMMUNICATIONS
The host computer and OpenDAC
communicate serially over one or two pair of
twisted wires per RS-422/485 in a multi-drop
configuration. They use Modbus ASCII or RTU
temperature values
®
®
®
I/O. As one of 247 slave devices on
for Modbus connects directly to two
for Modbus is an inexpensive,
®
scans and stores the I/O
®
®
for Modbus
MODBUS UNIT ON OPENDAC
for Modbus
format to code the command and the response
messages. Application programs running on
the host computer issue commands and then
await responses from the OpenDAC
communications speed is switch selectable
between 9600 and 56700 baud. The entire
network can span 4000 feet.
FAULT TOLERANCE
Each OpenDAC
communications watchdog timer to minimize
the impact of a broken Modbus link between the
controller and the master device. If activated,
the timer must be reset by an incoming message
within the prescribed period of time. If not, the
controller will force it’s outputs into a default
state.
SOFTWARE
Software drivers are available which simplify
the task of interfacing host programs written in
Visual Basic or C to the Modbus 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 DLL will assist
you in building custom Man-Machine Interfaces
using Visual Basic, Visual C/C
compilers running on Windows 95, 98 or NT.
®
SYSTEM
®
for Modbus has an internal
++
, or Borland
®
. The