Specifications

Glossary
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mandatory module
When an Advantys STB I/O module is configured to be mandatory, it must be
present and healthy in the Island configuration for the Island to be operational. If a
mandatory module is inoperable or is removed from its location on the Island bus,
the Island goes to a pre-operational state. By default, all I/O modules are not
mandatory. You must use the Advantys Configuration Software to set this
parameter.
master/slave model
The direction of control in a network that implements the master/slave model is
always from the master to the slave devices.
Modbus
Modbus is an application layer messaging protocol. Modbus provides client and
server communications between devices connected on different types of buses or
networks. Modbus offers many services specified by function codes.
MOV
metal oxide varistor. A 2-electrode semiconductor device with a voltage-dependant
nonlinear resistance that drops markedly as the applied voltage is increased. It is
used to suppress transient voltage surges.
MSB
most significant bit, most significant byte. The part of a number, address, or field that
is written as the leftmost single value in conventional hexadecimal or binary notation.
N
N.C. contact
normally closed contact. A relay contact pair that is closed when the relay coil is de-
energized and open when the coil is energized.
N.O. contact
normally open contact. A relay contact pair that is open when the relay coil is de-
energized and closed when the coil is energized.
NEMA
National Electrical Manufacturers Association