Model 290 - RS-232 to RS-422/RS-485 Concentrator - Wiring Hub

• Break RS-485 Limit, Expand to 496 Nodes
• 16 Port Capacity
• Each Port Settable to RS-422 or 2 Wire RS-485
• Provides Isolation Between Ports
• All Ports Surge Protected
• Increased System Reliability

Product Description

The Model 290 RS-232 to RS-422/RS-485 Concentrator offers a unique group of features for those applications using RS-422 and/or RS-485 for communications between a multiplicity of devices. Based upon a master-slave relationship. The Model 290 lets users expand RS-485 networks to 496 nodes, breaking the restriction of RS-485 that limits a network to 32 nodes. Greater network capacity is possible by cascading Model 290's. Industrial control applications are a prime example of the use of this type of communications protocol. The 16 discrete ports on the wiring hub provides the advantage of isolation between ports thus increasing overall reliability of the network. 

In a conventional RS-485 network a single node failure can crash an entire network, but now the Model 290 isolates any node failure from affecting the network. The master port of the Model 290 is configured for RS-232 and uses Transmit Data, Receive Data and Ground. The Model 290 incorporates a built-in interface converter to condition the signals between the master port and any of the slave ports. These are operator programmable to RS-422 or RS-485, simply by setting a dip switch for the respective port on the rear panel. The port connectors are RJ-11 type. Internal intelligence allows the Model 290 to support half duplex operation on the RS-485 single twisted wire pair without the requirement of RTS on the master port. Full duplex operation is supported on the RS-422 ports over two twisted pairs. Power for the Model 290 is supplied from a wall mounted transformer with an eight foot connectorized line cord. Every port is surge protected and the unit is equipped with a grounding stud to allow a connection to earth ground for diversion of the otherwise deadly effects of induced surges. 

The 16 ports are available on 6-wire, 6 position, RJ-11 connectors. Wiring is consistent with Telco standards wherein the inner two contacts represent the transmit pair for RS-422. The outer pair of contacts in the RJ-11 modular connector represents the bi-directional pair for RS-485 or the receive pair for RS-422.