Schneider Electric 890USE17700 User Manual

Page 188

Glossary

188

890USE17700 April 2004

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).

varistor

A two-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.

watchdog timer

A timer that monitors a cyclical process and is cleared at the conclusion of each
cycle. If the watchdog runs past its programmed time period, it generates a fault.