Glossary - Siemens SIMATIC S7-300 Manual

Glossary

2-/3-/4-wire connection
Methods of connecting resistance thermometers / resistances to the front connector of the
module, or loads to the voltage output of an analog input module.
2-wire transducer (passive sensor) / 4-wire transducer (active sensor)
Type of transducer ( 2-wire transducers: power supply via terminals of the analog input
module; 4-wire transducers: power supply via separate terminals of the transducer.)
Absolute encoder
Determines the distance traveled by reading a numerical value: When using absolute
encoders with serial interface (SSI), the path information is transferred synchronously and
serially according to the SSI protocol (synchronous serial interface).
Address
Represents the identifier of a specific address or address range. Examples: input I 12.1; flag
word MW 25; data block DB 3.
Backplane bus
Serial data bus for module intercommunication, and power distribution to the modules. Bus
connectors interconnect the modules.
Basic conversion time
Time required for the actual coding of a channel (integration time, plus all times required by
the internal control, i.e. the channel is fully processed when this time has expired.
Basic error limit
Represents the operational limit at 25 °C, relative the module's rated range.
Basic execution time
Cycle time of an analog IO module when all of its channels are enabled. Equivalent to
"number of channels x basic conversion time."
S7-300 Automation System Module data
Manual, 08/2006, A5E00105505-04
Glossary-1