3936-Z1A

* TRANSFORMER ISOLATION OF SERIAL HIGHWAY FOR HIGH NOISE ENVIRONMENTS
* BIPHASE MULTIPLEXING PROVIDES TRANS- FORMER-COMPATIBLE SIGNALS OVER A SINGLE PAIR
* BYPASS AND LOOP COLLAPSE ARE PROVIDED
* MEETS IEEE 583 AND 595 REQUIREMENTS
* TRANSIENT AND SHORT CIRCUIT PROTECTION OF HIGHWAY INPUTS AND OUTPUTS
* HYSTERESIS ON HIGHWAY LINE RECEIVER TO MINIMIZE FALSE TRIGGERING
* CRYSTAL-CONTROLLED OSCILLATOR FOR ACCURATE CONTROL OF THE DEMULTIPLEXER
* ACTIVE SIGNAL REPEATER IN RETURN PATH (SUPERCEDES 3932)

APPLICATIONS * AUXILIARY LOOP CONTROL FOR TYPE L-2 SERIAL CRATE CONTROLLERS
* SERIAL SYSTEMS IN A HIGH COMMON MODE NOISE ENVIRONMENT
* SERIAL SYSTEMS WITH HIGHER OPERATING SPEEDS OVER LONGER DISTANCES THAN CAN BE OBTAINED WITH D-PORT CONNECTIONS
* TRANSFORMER-ISOLATED HIGHWAY FOR SERIAL CRATE CONTROLLERS AND SERIAL DRIVERS

GENERAL DESCRIPTION

The Model 3936 U-Port Adapter provides auxiliary loop control when used with a Type L-2 Serial Crate Controller such as the Model 3952 or with a serial highway driver such as the Model 3992 or 3994 operated in bit-serial mode. This module is one unit wide. Only power connections are made to the Dataway. When loop control is needed for byte-serial applications, the Model 2958 U-Port Adapter is recommended. A serial highway driver and Type L-2 SCC's operated in bit-serial mode may be interconnected by a loop consisting of two pair, one for clock and one for data. While this connection is satisfactory for many applications, auxiliary loop control may be needed. The Model 3936 can be used to enhance serial system operation in the following way:

1. It provides bypass and loop collapse under control of the associated L-2 scc.

2. It provides a multiplexed signal and transformer isolation. This reduces interference with the data signals in high noise environments as well as al- lowing for increased operating speed and/or distance.

FRONT PANEL

   LEDs                                 State When On

PwR (green)                indicates that the necessary voltages for
                                   module operation are present (+6 volts,
                                  -6 volts and +24 volts).

 BYP (red)                 Indicates that the SCC is bypassed by the
                                  SCC bypass bit being set or the 3936 front
                                  panel switch being set to BYPASS.  The sig-
                                  nal is still passing through the demultiplexer-
                                  multiplexer.

 LC (red)                  Indicates that the SCC loop collapse is true
                                AND is enabled by strap option in the 3936.



Test Points

     TP1             Monitors the incoming signal on the go path after
                         the equalizer

     TP2             Monitors the incoming signal on the go path after
                        the line receiver (TTL level)

     TP3             Monitors the multiplexer output

     TP4             monitors the incoming signal on the return path
                        after the equalizer

     TP5             Monitors the transmitted signal on the return
                        path