Quick I/O connections
Faster I/O (input/output) wiring installation times are a requirement for users, machine builders, and integrators to stay competitive. Several methods help accomplish this; applying multiple solutions can offer the greatest benefit.
Any system that requires cable stripping wastes valuable time. It also wastes time and money to route individual I/O cables beyond 5 or 6 feet. Hard-wired or screw terminations can introduce unnecessary or premature failures.
Machine builders seeking to reduce build time and increase reliability can take advantage of:
Highly distributed I/O networking.
Networking I/O is an accepted way of getting data to the PLC. But why do I/O nodes need 16 or even more I/O points? Justifying their cost is possible only when most points are used. This means that sensor and actuator cable lengths are longer, cost more, and take longer to route. Highly distributed I/O designs use low-cost nodes with only a few points, installed at the precise location of use. Sensor cables are shorter, less costly, faster to install, and increase noise immunity.
Insulation displacement instead of cutting and stripping cables
It is time consuming to strip and prepare a multi-conductor cable. Insulation displacement technology is faster: Upon installation of the I/O module onto the base, the necessary connections are made. Typically, this takes only a few seconds, guarantees correct polarity, and assures consistent IP (ingress protection) rating. Two of the most common industrial I/O networks, AS-Interface (more than 14 million installed nodes) and DeviceNet (also several million), make use of this technology.
Tool-free installation of hardware devices.
A new trend in mounting I/O modules onto the network cable makes tools unnecessary. Cleverly designed levers can securely attach modules to the mounting bases using insulation displacement, eliminating need for screwdrivers.
Faster M12 connection technologies.
The M12 quick-disconnect design saves time. Various technologies offer even faster connections than turning a knurled nut several times. Half-turn designs differ; one is forward and backward compatible to all standard M12 connections, so it can be phased in gradually.
Networking E-stops and other safety input devices
An unprecedented level of enhancement is possible by networking e-stops and other safety devices. Some networks are certified for safety applications, removing the complexity, clutter, and cost when designing to CAT 4 safety. Installers can accomplish in minutes what previously took hours.
When all or some of the above technologies are employed, significant time savings can be realized. Not every technology discussed is applicable in all circumstances. But, any machine can utilize at least a few of these improvements, allowing greater cost advantages in globally competitive markets.
Phoenix Contact also offers Speedcon technology.
|Helge Hornis, Ph.D., is manager intelligent systems at Pepperl+Fuchs.|