Specifications

Glossary
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U
UDP
user datagram protocol. A connectionless mode protocol in which messages are
delivered in a datagram to a destination computer. The UDP protocol is typically
bundled with the Internet Protocol (UPD/IP).
V
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.
voltage group
A grouping of Advantys STB I/O modules, all with the same voltage requirement,
installed directly to the right of the appropriate power distribution module (PDM) and
separated from modules with different voltage requirements. Never mix modules
with different voltage requirements in the same voltage group.
VPCR object
virtual placeholder configuration read object. A special object that appears in the
CANopen object dictionary when the remote virtual placeholder option is enabled in
a CANopen NIM. It provides a 32-bit subindex that represents the actual module
configuration used in a physical Island.
VPCW object
virtual placeholder configuration write object. A special object that appears in the
CANopen object dictionary when the remote virtual placeholder option is enabled in
a CANopen NIM. It provides a 32-bit subindex where the fieldbus master can write
a module reconfiguration. After the fieldbus writes to the VPCW subindex, it can
issue a reconfiguration request to the NIM that begins the remote virtual placeholder
operation.