Technical data

Index Protocols and Communication Data List
B-13
P/N 7135049A
E 2007 Nordson Corporation
VBC_Siemens
Command (contd.)
Communication Monitoring
If the job identification is 0 (zero) and the melter is in Field bus mode, Field
bus communication failure is indicated on the control panel.
Possible faults
S Programming error. The master was programmed incorrectly with
Command=0.
S Field bus cable broken, defective or not connected
S Interruptions in communication, e.g. if the master is not switched on
S Defective or missing bus terminating resistor
S The network was not set up properly
S Sudden resets or crashes, e.g. due to electro-magnetic interference
S With PROFIBUS, also refer to Diagnosis Using Bus Port Plug LEDs in
the appendix Profibus-DP.
NOTE: When a fault occurs, the melter control system stops all motors that
are running.
Data Index
Indexes determined by the master are assigned to the communication data.
The data index is used to address communication data that is to be
transmitted or received (Also refer to Communication Data List).
If the Acknowledge data index of the receive data block is identical with the
transmitted data index, the job is completed.
Data index set to ”0” (zero) is interpreted as No data index.