Historical
IEC 61158-2 Ed. 5.0 b:2010
Industrial communication networks - Fieldbus specifications - Part 2: Physical layer specification and service definition
"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:
a) data integrity before data-link layer error checking;
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:
- for Type 18, Table 157 reduced tolerance to 5 %;
- for Type 18, in 32.5.3.1 removed minimum cable length;
- for Type 18, in 32.5.4. and R.2.2 cable reference removed;
- for Type 18, Table 160 and 161 terminating resistor value changed to 680 Ω. This bilingual version published in 2011-12, corresponds to the English version published in 2010-07."
International Electrotechnical Commission [iec]