Eicon Networks 1550 - Manual (Page 101)

Web Interface Settings Glossary 101
Data Encoding
Defines the type of data encoding used on the VHSI port.
This setting must match that of the remote system.
• NRZ: Enable Non Return to Zero encoding. Can be used for internal or external
clocking.
• NRZI: Enable Non Return to Zero Inverted encoding. Can be used with internal or
external clocking, and INT-DPLL (Internal Digital Phase Lock Loop) or EXT-DPLL
(External Digital Phase Lock Loop) with a line speed limit of 19,200 bps.
• FM0: Enable FM0 (also known as biphase space) encoding. Can only be used with
INT-DPLL clocking with a speed limit of 38,400 bps.
• FM1: Enable FM1 (also known as biphase mark) encoding. Can only be used with
INT-DPLL clocking with a speed limit of 38,400 bps.
Clocking
Defines how the VHSI port is clocked, which controls synchronization and the rate of
data exchange on the line.
• EXTERNAL: The port uses the clock supplied by the device it is connected to (DTE)
for receiving and transmitting.
• INTERNAL: The port generates an internal clock for receiving and transmitting, and
outputs this clock on the interface for use by the device it is connected to (DCE).
• EXTDPLL: The port employs a DPLL that uses a DCE generated clock at 32 (NRZI)
or 16 (FM) times the data rate.
• INTDPLL: The port employs a DPLL that uses an internally generated clock at 32
(NRZI) or 16 (FM) times the data rate.
Line Speed
Defines the speed at which the VHSI port operates, in bits per second (bps). Certain
restrictions inherent to the network to which the Eicon 1550/1551 is connected can
limit throughput. Speeds in excess of 128 kbps are possible on dedicated lines, but
public X.25 networks may be as slow as 2400 bps. This parameter is used only when
Clocking is set to INTERNAL. When external clocking is selected, the device providing
the clock sets the line speed. Default: 64000.