Volatile Material Handling for IBM – Issue 17, 2010
When IBM needed a control and delivery system for Silane gas at the T. J. Watson Research Facility in Yorktown Heights, NY, they turned to KCC Software of Huntsville, AL.
Silane gas is essential in an ultra-pure method of applying silicon in the manufacturing of semiconductors and solar panels. The SiH4 compound, however, is extremely volatile and will combust if exposed to atmosphere. Thus, the storage and delivery of this gas to their many labs has to be handled very carefully.
In addition to storage and on-demand delivery of the gas to dozens of production tools in multiple labs, the system also manages many automated purge routines to safely remove the dangerous gas from several points throughout the distribution network. Many of these purge routines require synchronized processing by multiple PLCs. Thus, networking and PLC-to-PLC communication were central aspects of this system.
The system that KCC Software developed is a network of six PLCs, touch panels, and a supervisory PC. The main PLC is a DirectLOGIC DL205 series with a D2-260 CPU. This PLC contains three Ethernet connections, multiple analog and thermocouple inputs cards, discrete input cards and discrete output cards distributed through the main and remote bases. (Fig. 1)
Each lab in the research center has a DL06 PLC. Each DL06 has an additional discrete I/O card and two analog input cards. All PLCs are networked through 100 Mbit Ethernet connections using ECOM100 cards. (Fig. 2)
Each PLC has a C-more touch panel displaying interactive graphics with password-protected configuration and control of the system. Additional 15-inch C-more touch panels are located at critical points throughout the facility, allowing personnel to view the status of all PLCs, the central distribution system, each lab control system, and the status of each tool receiving gas from the system (Fig. 3). The touch panels also include an electronic version of the operations manual allowing quick references to the system documentation.
“KCC Software was chosen to develop a new PLC-based gas delivery control system for our facility. Scott Martin and his colleagues were given the task of developing software and hardware to implement our needs on a very tight time schedule. This was done while allowing us to continue to operate the older delivery system in tandem until time of change over. Scott worked hand-in-hand with us to fully understand our current system and to implement improvements with the new system along the way. KCC Software’s commitment to detail is unparalleled and was one of the main reasons for a trouble-free and on-time project,” says Ray Sicina of IBM Research.
One important feature provided by the touch panels is that all pressure transducers and thermocouples are trended with alarm setpoints included in the trend graphs. If a problem occurs, IBM can review the key system operating parameters looking for abnormal behavior.
For safety purposes, critical signals were wired from one PLC to another in a fail-safe form of handshaking. Since hundreds of tags are shared between the central controller and each lab controller, extensive use of Network Read and Write commands was implemented. This allows for continuous “behind the scenes” communications without adding code to the lab DL06 PLCs, and without the need to manage or synchronize polling. This network communication capability designed into the AutomationDirect PLC family was a vital aspect to the success of this distributed system.
The system includes a supervisory PC which contains a central database for all process parameters and alarms for every component in the system. This supervisory application was developed using Think & Do PC-based software, with a Modbus interface to each PLC. The PC application includes interactive color graphic screens showing the active state of the entire distribution system with current valve states, active gas flow, and all pressure transducer readings.
In addition to the DirectLOGIC PLCs, expansion cards, C-more touch panels, and Think & Do software, KCC Software also selected Rhino power supplies, STRIDE Ethernet switches, cables, pushbuttons, lamps, circuit breakers, wire, terminal blocks, DIN rail, and many other components from AutomationDirect. The exceptional customer support and fast response to orders have always been appreciated by KCC Software; in this project, it also surprised and impressed IBM. AutomationDirect’s products and support created a foundation upon which KCC Software was able to build an exceptional system that will keep IBM safe and productive for decades to come.
By Scott Martin