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kb:production:s7-communication:iso-on-tcp

02 ISO on TCP

aka TPKT

Name ISO Transport over TCP
ISO
RFC RFC 1006

Implements ISO transport services on top of the TCP. TCP port 102 is reserved for hosts which implement this standard. The main points are TSAP addressing and the detection of packet boundaries.

Packet Structure
ISO on TCP TPKT Hdr TPDU

TPKT Header

Byte Value Description
[0] 0x03 Version
[1] 0x00 Reserved
[2] TPDU Length (MSB)
[3] TPDU Length (LSB)

The actual value for the TPDU Length must be calculated dynamically from the size of the payload

TPDU

Contents depend on packet type, see ISO TP.

kb/production/s7-communication/iso-on-tcp.txt · Last modified: 2021/05/06 10:21 by manuel.sebald