Schneider Electric 890USE17700 manual Pdm, Pdo, Plc

	Glossary
PDM	power distribution module. A module that distributes either AC or DC field power to
	a cluster of I/O modules directly to its right on the island bus. A PDM delivers field
	power to the input modules and the output modules. It is important that all the I/O
	clustered directly to the right of a PDM be in the same voltage group—either
	24 VDC, 115 VAC, or 230 VAC.
PDO	process data object. In CAN-based networks, PDOs are transmitted as unconfirmed
	broadcast messages or sent from a producer device to a consumer device. The
	transmit PDO from the producer device has a specific identifier that corresponds to
	the receive PDO of the consumer devices.
PE	protective earth. A return line across the bus for fault currents generated at a sensor
	or actuator device in the control system.
peer-to-peer	In peer-to-peer communications, there is no master/slave or client/server
communications	relationship. Messages are exchanged between entities of comparable or
	equivalent levels of functionality, without having to go through a third party (like a
	master device).
PLC	programmable logic controller. The PLC is the brain of an industrial manufacturing
	process. It automates a process as opposed to relay control systems. PLCs are
	computers suited to survive the harsh conditions of the industrial environment.
preferred module	An I/O module that functions as an auto-addressable node on an Advantys STB
	island but is not in the same form factor as a standard Advantys STB I/O module and
	therefore does not fit in an I/O base. A preferred device connects to the island bus
	via an STB XBE 1000 EOS module and a length of STB XCA 100x bus extension
	cable. It can be extended to another preferred module or back into a standard island
	segment. If it is the last device on the island, it must be terminated with a 120 Ω
	terminator.
premium	An Advantys STB network interface module designed at a relatively high cost to
network	support high module densities, high transport data capacity (e.g., for web servers),
interface	and more diagnostics on the island bus.
prioritization	An optional feature on a standard NIM that allows you to selectively identify digital
	input modules to be scanned more frequently during a the NIM’s logic scan.
process I/O	An Advantys STB I/O module designed for operation at extended temperature
	ranges in conformance with IEC type 2 thresholds. Modules of this type often feature
	high levels of on-board diagnostics, high resolution, user-configurable parameter
	options, and higher levels of agency approval.

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