Bus-based communication systems are an integral part of today’s modern office environment. The Ethernet with the RJ 45 I/O connector has become the standard for Local Area Networks (LAN).
The fast USB 2.0 and Firewire IEE 1394 b protocol has evolved into the standard interface protocol for computers and accessories. The slower CAN and Profibus networks are predominantly used in industrial control applications.
Increasing demand for higher data transfer rates and the requirement for compatibility with other networks, such as office LANs, make the Ethernet an ideal choice for industrial networks and automation.
The fast emergence of new Ethernet-based industrial networks demonstrates the migration of such systems from the clean office environment into the dirty world of industrial applications.
An increasing number of leading industrial network manufactures use the Ethernet or even faster systems for their industrial network topology.
However, the availability of a suitable connector remains a problem. Neither the PC-style RJ-45 nor the modern Firewire or USB 2.0 connector is designed for operation in the severe industrial environment.
Insufficient protection against moisture, not enough mechanical ruggedness, and complicated or insufficient locking systems provide serious challenges for the system designer.
Even older standard connectors could not meet all the requirements for reliable operations in an industrial environment.
The industry-standard 9-position D-Sub connector, for example, cannot meet the IP 67 requirement for industrial connectors. The popular M12 standard lacks a fast and reliable locking system.
Modified RJ-45 connectors are often too bulky:
In summary, the industry is looking for suitable connectors for use in bus-based networks operating in dirt and water, exposed to high vibration and protected against electromagnetic interference (EMI). Modified RJ-45 connectors with potted housings are appearing on the market. However, they are often too bulky and have yet to demonstrate their reliable use on industrial machinery.
ODU has many years of experience in the industrial market and offers a number of bus-qualified, rugged and compact connector solutions. Two product families, the ODU Mac and ODU Mini-snap can meet the industrial challenges.
The modular, rectangular ODU Mac connector has found many applications for several decades in industrial docking and measurement and control systems.
Depending on the application, the ODU-MAC can be equipped with a quick-lock spindle or a latching system based on locking levers.
In either case, the locking system is reliable and connector mating or demating is done quickly and easily.
The modular concept of the connector, with many different modules and contact types, makes it easy to design connectors for a wide range of industrial uses.
High-density modules with a large contact count are suited for bus systems with low data transfer rate requirements.
A special EMI-shielded bus module is available for use in faster, more modern bus system based on the Firewire or USB 2.0 protocol.
The ODU-Mac can have electrical contacts for various voltage or power levels, pneumatic couplers, or fiberoptic contacts side-by-side in the same connector housing.
Coax and fiberoptic contacts are available for EMI-sensitive applications.
Cylindrical push-pull connectors:
The ODU Mini-snap product family of compact cylindrical push-pull connectors available from Clarke & Severn Electronics offers another solution for critical applications in industrial bus systems.
The metal housing of the ODU Mini-snap provides good EMI shielding. The reliable push-pull locking system makes mating and demating easy and quick. Accidental demating of the connector is nearly impossible.
Push-pull connector ODU Mini-snap, size 0, 7 positions
The ODU-Mini-snap product line has a wide range of insert arrangements, contact styles and connector sizes.
It is also available with environmental protection to IP 68. Several different designs of panel-mounted receptacles allow crimp or solder termination to wires or even direct soldering to PCBs.
Application tooling for crimping is available for all common wire sizes.
The two product families offer exceptionally rugged, industrial-qualified connectors for bus-based networks. Independent test laboratories have verified the suitable use for bus-based networks.
Measurement of connector parameters such as signal attenuation, impedance, interference and crosstalk at 400 MB/sec has confirmed that the connector performance exceeds the requirements of Firewire Standard IEEE 1394-1995.
This demonstrates without a question that the connectors are suitable for use in high-performance, bus-based networks.
The connectors can also be used in bus systems with lower data rates and lower overall performance requirements.
5-position Bus module for multiple, shielded connectors
The question of a connector’s bus-suitability can only be answered by considering all electrical performance requirements. The connector has to be seen as part of the overall system.
Often, the attenuation and interference values of a connector are much less than those of the attached cables. To make a proper assessment of the network performance requires that all components are included in the evaluation.
This requirement is, of course, part of all industry standards.