CHAPTER 35
Network connection
405.1200.037.2 - Rel.: 2.21 of 25/02/2008
35-10
Interbus-S A VT equipped with a network card can be connected within a network as a
slave (a passive station that can only transmit data after receiving a request
from an active station). The master communication card, generally inserted
in a PLC station, transmits and recieves information from the slaves. There
can be more than one slave connected to a single master in a network.
Interbus-S: VT
operation
The slave VTs are seen generally as dedicated areas of memory in the
PLC’s I/O area, or alternatively in other data areas made accessible by the
configurator of the master, which are used by the PLC and VT to exchange
data. The size of the I/O area of each VT participating in the network is 4
words (8byte).
Interbus-S:
Configuration
software
There are 3 types of software that play a part in configuring the network:
• VTWIN
• FB
• Configuration software for network master
These types of software require parameters that coincide.
VTWIN:
The parameters that must be set in the VTWIN project of every ter-
minal connected in the network are:
• Timeout for testing the connection between the VT and PLC.
FB:
This is a program supplied by ESA to be loaded into the PLC. This
program is used to check the network parameters set and the data
exchange. It varies according to the type of PLC (make and model).
Besides the parameters which we have just seen in VTWIN, the
incoming FB requires other information related to the PLC that will
be hosting it. This information is contained in a text file on the disk
entitled “VT-INTERBUS Installation SW”.
Network master configuration software:
This software is supplied by the producer of the network master.
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