Acceptance of programmable controllers (PCs) over the past 15 years
is directly attributable to their user-friendliness, both in terms of
hardware, and the familiar relay ladder diagram language by which the PC
was programmed. However, early applications concentrated within those
discrete or sequential logic segments typically found in automotive
manufacturing and material handling applications.
James F Shanley, Supervisor, Product Development and Support
Products, Allen-Bradley Systems Div, Highland Heights, OH, says that
today PCs are applied in every major industrial sector as well as the
auto industry. Applications of PC’s range from material handling
to continuous process control; functionally PCs are used for control
problems requiring analog, digital, high order math, discrete logic, and
computational capabilities. It has become evident that new industries,
applications, and functional capabilities place new demands particularly
on program development and management aspects of the control system.
To provide a sufficient range of support tools needed to cover this
breadth of requirements, today’s PC manufacturer must provide a
multiplicity of solutions to meet these and future needs. One of the
most effective methods of meeting new customer requirements, is to
provide program development functionality in a software-base rather than
a hardware form. The advantages are:
* Configurability. By simply loading the appropriate software into
a programming terminal, for example, the functionality of the device can
be changed to program in a different language, program a different PC
type, or provide a different support function such as annotating the
control logic with text comments or accumulating data from the PC for
* Expandability. As new capabilities are added, software modules
supporting those capabilities can be easily added by the customer to his
program development hardware.
* Upgradability. New features of the software can be made
available to current customers, generally through a software update
subscription program, to allow the customer to utilize improved or added
* Multipurpose. If the software is designed for use with
industry-standard hardware, the customer easily can use that hardware
with other software for purposes such as inventory management, word
processing, and so on.
In keeping with new user requirements, a new standard for control
system program development and support has been introduced by
Allen-Bradley. The Integrated Program Development and Support System
(IPDS) is a family of software products that provides an integrated
environment for development, documentation and support of control
programs on A-B programmable controllers.
IPDS is a multipackage concept, based on the interaction of A-B
programmable controllers with:
* Personal computer products–IBM PC/XT, 5531 industrial computer,
the new PC/AT, and Compaq Plus.
* Supermini-computers–DEC VAX 11/730, 11/750, 11/750, 11/785, and
Micro VAX I
* Future Allen-Bradley industrial terminal products.
Use of the software in conjunction with any of these hardware
devices will provide the control system user with the ability to:
* Program off-line. Create and edit a control program with the
programming device disconnected from the programmable controller.
* Download. Transfer a control program from the programming device
into the programmable controller.
* Upload. Transfer a control program from the programmable
controller to the programming device.
* Document a control program with text commentary for archiving or
According to the company, introduction of IPDS packages will occur
throughout 1985. Each development will build on capabilities of the
release before it. The first release, scheduled for the second quarter,
will be PLC-2 family software package designed for the IBM PC/XT
personal computer. The package’s capabilities will include
off-line program development and editing for the entire PLC-2 family;
download for 1770-SB and Data Highway; and program documentation.
For more information, circle E36.