BAS EN 61158-2:2012

IEC 61158-2:2010 specifies the requirements for fieldbus component parts. It also specifies the media and network configuration requirements necessary to ensure agreed levels of:<br /> a) data integrity before data-link layer error checking;<br /> b) interoperability between devices at the physical layer. The fieldbus physical layer conforms to layer 1 of the OSI 7-layer model as defined by ISO 7498 with the exception that, for some types, frame delimiters are in the physical layer while for other types they are in the data-link layer. This fifth edition cancels and replaces the fourth edition published in 2007 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:<br /> - for Type 18, Table 157 reduced tolerance to 5 %;<br /> - for Type 18, in 32.5.3.1 removed minimum cable length;<br /> - for Type 18, in 32.5.4. and R.2.2 cable reference removed;<br /> - for Type 18, Table 160 and 161 terminating resistor value changed to 680 &Omega;. This bilingual version published in 2011-12, corresponds to the English version published in 2010-07.