Specifications

CP143 H1 / TCP/IP manual The CP143 H1 / TCP/IP network board
Rev. 00/07 4-13
4.2.3.2 Generation of a multicast address from the ethernet address
The TP4 protocol stack generates a MC address from the ethernet address. This function is required
as the ethernet controller (hardware) uses the MC address for message filters.
4.2.3.3 Broadcast
The broadcast address is always FFFFFFFFFFFFh.
4.2.3.4 block size
Every configured interface of the CP must be synchronized by the handler module SYNCHRON
when a PLC is started. This applies to every type of start-up of the respective PLC:
• OB20 for a new start
• OB21 for a manual re-start
• OB22 for a re-start after a mains power failure
block size CP block size in bytes
1
0 Default block size for a CPU. This may differ,
depending on the type of CPU.
116
232
364
4 128
5 256
6 512 (for the READ/WRITE function)
255 512
Tab. 4-4: block size
1)
The first transfered block for the READ/WRITE function is 16 Bytes (length of READ/WRITE
Header) shorter as the set block length.