PCs, Flowcharts, and SDS Speed Production at Silicon Graphics

Smart Distributed System

By Control Engineering Staff February 1, 1997

F or Ron Stone, applications manager for FloStor Engineering in Hayward, Calif., Honeywell’s Smart Distributed System (SDS) proved to be the answer to a two-year search. FloStor, a leading materials handling integrator in Northern California, serves companies that manufacture and distribute products from computers to automobiles.

rkstations, approached FloStor with a request for just such a system–and with a very tight deadline.

rther work or testing.

at it will be much easier to accommodate those changes in the flowchart environment compared to configuration of the control network.

Faster than a PLC

The Smart Distributed System sped the installation process at SGI by allowing FloStor engineers to simplify the control programming, bring the system online, and quickly debug it. While the older PLC system provided some of these features, Mr. Stone says the Honeywell PC system gives his SGI customers much more control over the process.

ation–not cost–was the critical factor.

rather than interfacing with I/O boards and trying to use less expensive but unintelligent devices.’ Using I/O boards means lost diagnostic capability–a major issue–in addition to exposing the installer to other problems which are much more difficult to uncover and address.

Adaptability a key

SDS is an ideal match for many of FloStor’s Silicon Valley customers who have constantly evolving product lines and need to get their production running as quickly as possible. In the initial stages of many projects, FloStor usually lacks a complete set of specifications and makes constant modifications as it brings a project up to speed. ‘Silicon Graphics doesn’t know exactly how it is going to use the line,’ says Mr. Stone. ‘So our task is to provide the flexibility that allows SGI to move product around as its needs evolve.’

SDS At a Glance

S mart Distributed System (SDS) was introduced by Honeywell Micro Switch in early 1993 and formally opened to other vendors the following year. SDS nodes are built on CAN (Control Area Network) chips, which were developed for the automobile industry.

lower transmission speeds. SDS does not lend itself to repeaters. If many nodes and long distances are needed, SDS could be fed into another higher level bus. Significant branching could also be achieved with active hubs.

ess information at burst speed (maximum message rate) without dropping messages. When this is accomplished SDS can be the most efficient network because it reports only changes at the nodes. The user must decide if the loss of an attendance check on every scan (attendance polling) is acceptable.


PC Control for the Factory Floor–It’s Here to Stay

A s we look to the year 2000, there’s an exciting future in store for manufacturing. ‘Technology threads’ are converging on the factory floor, and as they meet, users will find unparalleled productivity gains. Those technology ‘threads’ are PC control, device-level networks, and smart devices.

a robust, open, device-level network.

r material handling equipment to packaging equipment, canning lines, and automotive assembly lines–harsh environments where speed, flexibility, and maximum uptime are critical.

igence resides in the field devices, thus redefining the function of host controllers, PCs or otherwise.

–Steve Glaze, Honeywell Micro Switch

Power devices on SDS

GELink MC, as part of a completely integrated control system incorporating SDS and GE Fanuc Series 90/30 PLC SDS interface modules, provides users with the ability to connect power devices such as contactors, motor starters, and circuit breakers to a real-time control network. Four 10 A outputs and four discrete inputs can be handled.


Adjustable-frequency drive

This new serial communication option makes it possible to completely control and diagnose the AF-300 Micro $aver adjustable-frequency drive from the SDS bus. The Micro $aver drive is available for 230 V ac (single and three-phase) and 460 V ac input with ratings from 0.25 to 5 hp.


Analog I/O for SDS

This module supports up to four analog inputs or outputs as a single bus load. Each 12-bit analog channel uses one bus address and has an average update time of 8 msec per channel. The analog circuitry requires a 10-30 V dc power source.


Multipurpose valves

The Mark 4 manifold is a multipurpose 4-way valve, 2- and 3-position, which incorporates the manufacturer’s reliable spool and sleeve valving action. It has a C v of 0.4. Sandwich pressure regulator, sandwich speed control, and push-in fittings are available.


AC and DC output drivers

The SDS Output driver is a device which can be used to control solenoids, motor starters, pilot lights and other remote electrical devices over the SDS bus. AC and DC versions are available; the DC version can obtain its power from the SDS bus.


Serial Manifolds

This new line of SDS-compatible Serial Manifolds (SM) range from miniature to large 2-way, 3-way, and 4-way configurations spanning various flow ranges. Many of the standard valve options such as regulators, flow controls, and ‘add-on’ style manifolds are available.


Communication link for VSD

An interface card allows MagneTek’s compact GPD 333 variable-speed ac drive to be connected directly to the SDS network. The GPD 333 is available in ran-ges of 1 to 5 horsepower, 230 or 460 V ac. The SDS network interface for the larger GPD 515 will follow.