Technical data

Index Protocols and Communication Data List
B-2
P/N 7135049A
E 2007 Nordson Corporation
VBC_Siemens
Control Modes (contd.)
Field Bus
In Field bus mode, the master controls the melter:
S Control access only from master. Control via the interfaces Standard I/O
and Key-to-line.
S Parameter input only via master
S On the control panel, all parameters can be displayed but not changed.
Data Interface
When data is exchanged between the master and Nordson melters, the
data is accessed via indexes (Data index). All of the communication data is
compiled in the communication data list.
The index process works with small data blocks. This prevents the field bus
from being burdened with unnecessary data.
In the selection of the index protocol, the operator determines how the data
blocks are transmitted.
Transmission and Receive Data Block
NOTE: Communication is always seen from the point of view of the master.
Two data blocks aid in communication. A block transmitted by the master is
the same as a command to the Nordson melter; a received data block is the
same as a reply from the Nordson melter.
The master may not formulate and transmit a new command until after
arrival of the receive data block.