Multi-Tech Systems FR111 owner manual Between Frames, Encoding Scheme, InterFrame Timer in mS

Note: The MultiFRAD always provides the clocking signal to the sync device. The MultiFRAD 100's data port can not be set to external clocking, it is always internal clocking.

Between Frames

The Between Frames parameter must be set to match the idle condition of the synchronous device connected to the data port. The Between Frames determine what happens when the synchronous data line is idle (i.e., no data frames are being transmitted). The default condition is to continuously send SDLC flags (Flags). The other condition is the mark state (Mark). The transmit LED will be off during idle time if the synchronous device is in the mark state during idle conditions.

Encoding Scheme

The Encoding Scheme parameter refers to the fact that synchronous data can be encoded by using either NRZ (Non-Return to Zero) or NRZI (Non- Return to Zero Inverted) method. This parameter must match the synchro- nous device’s encoding. The default is NRZ. With NRZ encoding, the data is represented normally. With NRZI encoding, a logical one is represented by no transmission and a zero is represented by a transition at the beginning of the bit. Most synchronous devices can be configured for either NRZ or NRZI. If a synchronous device is not configurable, it most likely is set to NRZ. Refer to the device’s user documentation for the encoding method.

InterFrame Timer (in mS)

The InterFrame Timer parameter can be changed to make the MultiFRAD wait a specified length of time between frames. You can choose Off and delay times of 2,5,10 and 15 milliseconds. A typical use for this parameter is to simulate transmission delays encountered with equipment that toggles hardware signals after transmission of each frame, like PC cards used to connect to legacy systems. The following options can be specified for the timer: Off, 2mS, 5mS, 10mS, and 15mS. The default is off.

57