Just as Old MacDonald had a farm filled with different animals, the marketplace is stocked with many choices for the I/O and terminal blocks that serve as the connectivity core of every modern machine.
“Ethernet is the modern approach to I/O,” claims Jim Lamberson, senior design engineer from Sensoray (sensoray.com). “It is electrically isolated, so pesky communication ground loops can be eliminated. A single, standardized cable connects the control computer to the I/O system, reducing cable clutter and cost. An Ethernet I/O system can be located far from the host computer and distributed so its I/O interfaces reside at optimal locations close to the field wiring. Since field wiring connects directly to the remote I/O system, there is no need for external termination boards. Perhaps most importantly, Ethernet offers protection from obsolescence. Ethernet is available for virtually every hardware platform and will be available for the foreseeable future.”
Jason Haldeman, product marketing specialist at Phoenix Contact (phoenixcon.com), agrees. “Ethernet provides cabling flexibility that traditional I/O networks lacked, such as supporting ring, star or tree structures using copper, fiber and wireless media,” says Haldeman. “No traditional network can support this many variations without costly conversion devices. Ethernet also was designed to support multiple protocols, allowing a single network to handle all the machine builders’ communication needs from the monitoring system down to the sensor level.”
Helge Hornis, Ph. D, manager, intelligent systems, at Pepperl+Fuchs (am.pepperlfuchs.com) believes engineers are increasingly scrutinizing the mechanical design of the I/O just as much as they analyze the overall manufacturing simplicity, in an effort to reduce I/O installation costs. “An important aspect of machine I/O relates to functional safety,” he explains. “Safety networks provide machine builders with ever-increasing design flexibility, reducing the cost of safety systems while increasing diagnostic capabilities.”
I/O terminals add more functionality to reduce the need for extra interfacing devices or “black boxes” in systems, says Graham Harris, president, Beckhoff Automation (beckhoff.com). “Intelligent I/O requires fewer connections for better reliability, smaller cabinets and often less software,” he says.
|ETHERNET I/O MODULES
A firmware enhancement to Adam-6000 Ethernet I/O modules adds peer-to-peer (P2P) and graphic condition logic (GCL) functionality. Peer-topeer functionality can actively update input channel status to specific output channels. Data will transfer automatically, with no extra controller or programming. Graphic condition logic is a Windows-based software utility that adds control logic between input and output without extensive programming.
Advantech, Industrial Automation Group
|LOW INSTALLATION COST
Line of IEC terminal blocks meets applicable UL, CSA and IEC standards and are rated for Code 1, factory wiring only, and Code 2, both factory and field wiring. Screw clamp terminal blocks are available from 20 A to 35 A, in both spring and screw clamp. Specialty blocks include ground, multi-level, sensor, multi-conductor, fuse holder and disconnect.
Bus couplers provide flexible IP20 and IP65/67 EtherNet/IP I/O connectivity, while integrated I/O lowers installed costs. The Inline bus coupler connects a complete range of up to 61 IP20 modules. For distributed machine mount IP65/67 applications, the Field-Line EtherNet/IP bus coupler connects up to 16 modules.