Schneider Electric 890USE17700 manual

	Glossary
Rx	reception. For example, in a CAN-based network, a PDO is described as an RxPDO
	of the device that receives it.

S

SAP	service access point. The point at which the services of one communications layer,
	as defined by the ISO OSI reference model, is made available to the next layer.
SCADA	supervisory control and data acquisition. Typically accomplished in industrial
	settings by means of microcomputers.
SDO	service data object. In CAN-based networks, SDO messages are used by the
	fieldbus master to access (read/write) the object directories of network nodes.
segment	A group of interconnected I/O and power modules on an island bus. An island must
	have at least one segment and, depending on the type of NIM used, may have as
	many as seven segments. The first (leftmost) module in a segment needs to provide
	logic power and island bus communications to the I/O modules on its right. In the
	primary or basic segment, that function is filled by a NIM. In an extension segment,
	that function is filled by an STB XBE 1200 BOS module. (An island running with a
	basic NIM does not support extension segments.)
SELV	safety extra low voltage. A secondary circuit designed and protected so that the
	voltage between any two accessible parts (or between one accessible part and the
	PE terminal for Class 1 equipment) does not exceed a specified value under normal
	conditions or under single-fault conditions.
SIM	subscriber identification module. Originally intended for authenticating users of
	mobile communications, SIMs now have multiple applications. In Advantys STB,
	configuration data created or modified with the Advantys configuration software can
	be stored on a SIM and then written to the NIM’s Flash memory.
single-ended	An analog input design technique whereby a wire from each signal source is
inputs	connected to the data acquisition interface, and the difference between the signal
	and ground is measured. Two conditions are imperative to the success of this design
	technique—the signal source must be grounded, and the signal ground and data
	acquisition interface ground (the PDM lead) must have the same potential.
sink load	An output that, when turned on, receives DC current from its load.
size 1 base	A mounting device, designed to seat an STB module, hang it on a DIN rail, and
	connect it to the island bus. It is 13.9 mm wide and 128.25 mm high.

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