I-O Display Systems Basic I/O Product - Manual (Page 6)

The Basic I/O 1
1-1(Vol.1)
THE BASIC I/O:
BASIC I/Os are a family of small, industrial grade, remote data acquisition and control
systems which exchange data with a Host computer via a serial communications link.
Controlled by a wide range of software running on a Host computer, Basic I/Os are located
near the sensors and actuators. The serial link eliminates the need for expensive and noise
prone signal wiring between field sensors and actuators, and a central control room.
Each BASIC I/O system consists of one logic board connected to a 4, 8, or 16 position I/O
module mounting rack. This combination is then field configurable to accept either analog or
digital electrically isolated input or output modules which can interface to a wide variety of
sensors and actuators.
BASIC I/O networks can service over 4000 analog and/or digital I/O lines in various
combinations.
User selected serial communications between the Host and the first BASIC I/O can be RS-
422 or RS-485. These communications links allow the units to operate up to 5000 feet apart.
Baud rates from 300 to 38,400 are available.
The BASIC I/O instruction set core complies 100% with that of the OPTO- 22 Optomux ™
.
With this ASCII character, speak-only-when-spoken-to protocol, a Host transmits inquiry
requests to the BASIC I/O to determine the status of its various process inputs. Similarly, the
software in the Host computer makes control decisions and transmits instructions to the
BASIC I/O, which in turn, makes the proper changes to its various outputs. Both the Host and
its communications link are essential elements in this data acquisition and process control
scheme.
Software for use with the BASIC I/O system can be obtained from a variety of sources.
Nearly every third party SCADA software vendor has developed a driver which is compatible
with this system. In addition, the communication protocol employed by the BASIC I/O
product is a published ASCII printable standard. This makes developing your own software a
simple matter. duTec also offers a software solution called EASY I/O. With this package,
custom QuickBASIC source code is generated to fit the signals generated to fit the signals
located on the BASIC I/O. Once configured, a simple data acquisition program is
automatically generated. This sample can then be altered to fit the particular needs of the user.