

The OmniMux 400 is an IBM compatible multiplexer that provides part or full local or remote 5250 and 5250 Express twinax controller connectivity to a distant location. It replaces up to eight AS/400 twinax cables with a single link. This link may be a twinax, twisted pair or a multi-mode or single-mode fiber pair. Optionally, the OmniMux can eliminate the twinax distribution box ("brick") and provide a direct single cable connection to the host controller, replacing all host controller twinax with a single DB25 cable. The OmniMux supports up to 56 addresses per link.
The OmniMux operates as a multiplexer (Mux), a demultiplexer (Demux), a demultiplexer-star (Demux-Star) or a star.
In the Mux and Demux modes, the OmniMux operates in pairs. On the host side, the Mux is connected to the local or remote controller’s twinax connectors, concentrating their twinax ports into a single link. At the far end, the Demux recreates each host port. Each port behaves as the original host port it is recreating. It can connect to the distant workstations via twinax daisy chains, twisted pair star hubs, such as the OmniStar™, or via fiber to desk repeaters, such as the OmniRepeater FTD.
In the Star mode, the OmniMux delivers twisted pair or twinax connectivity to the workstation while providing fiber connectivity back to the host end. The fiber conversion at the host end can be done using any OmniRepeater fiber converter.
The Demux-Star mode is used for multi-drop applications, when seven or less workstations at the far end are required. In this configuration, the OmniMux with an OmniMux XL multi-port mux supports the multi-drop requirement and allows a single host port to be selected for delivery to the far end.
The OmniMux utilizes a Digital Phase Locked Architecture (PLA). It facilitates data synchronization of data rate variations of up to -2% to +4%. It also facilitates a high degree of noise and crosstalk immunity. Each port is monitored and each data packet is analyzed for validity and errors. Noisy, shorted or open ports are automatically ignored and only valid data is processed. The retransmitted data is repeated, regenerated and reshaped; this ensures its reliable delivery to its destination.
The Express models operate with both the 5250 and 5250 Express protocols. Each port provides data rates of 1 Mbps for standard 5250 and 2 Mbps for 5250 Express protocol.
The host and workstations can be connected via twinax, RJ11/45 twisted pairs or a 25-pin DB25 cable. The twisted pair polarity control allows interface to different baluns.
Utilizing two links simultaneously provides a hot backup connection for fault tolerance in critical applications.
The OmniMux diagnostics detect and display true port activity and parity errors. Each port is monitored for valid frame header patterns, a detected pattern is displayed via a per-port green Activity LED. The data is analyzed for parity errors; a detected error is displayed via a per-port red Error LED. These features assist in installation and monitoring of the OmniMux operation.
The OmniMux 400 is completely software transparent and no setup or any changes are required.
Inputs: The OmniMux 400 is built around a Digital Phased Locked Architecture (PLA). It allows the independent monitoring and processing of data signals at each individual port, discriminating between true data and noise. A priority mechanism increases isolation between individual ports, reducing any crosstalk effect. The incoming Manchester encoded data is over-sampled at a rate of 16 samples per bit cell. This sampling rate is instrumental in the digital filtering of noise. A unique clock extraction technology facilitates the synchronization to data, with frequency variations of -2% to +4%.
Processing: Once the data has been recovered and synchronized, it is processed internally for validity. The processor analyzes the Frame Header, expecting at least 3 Sync bits followed by a Code Violation. When a legal Frame Header is detected, the port is "marked" active and the data is allowed to be retransmitted.
Outputs: The retransmitted data is fully regenerated and reclocked. Lost sync bits are restored, and the data is reclocked at a 50% duty cycle, eliminating any accumulated phase shift and clock jitter. The regenerated signal is restored to its nominal shape and amplitude and the pre-distortion logic compensates for anticipated phase shift and attenuation.
Displays: Per port true data activity and parity errors are displayed by green and red LEDs. The green activity LEDs assist in monitoring signal strength and polarity. The red Parity Error LEDs assist in monitoring connectivity quality, signal strength, impedance mismatches and reflections.
Auto Link Backup: Utilizing two links simultaneously provides link redundancy. The primary F/O link can be backed up by a "Standby" twinax or UTP link. Switching between the primary and secondary links is done automatically by the hardware. The Activity LEDs report the activity of each link.
Legend:
TWX= Twinax
F/O= Fiber Optic