System with online functionality
©
COMSOFT
69
8.4 Signal level measurement
Figure 64:
Signal level measurement
The
NetTEST II
measures the RS485-driver output level of
each individual DP Slave and displays them in a bar graph.
Below the bar graph the DP Slave address is indicated. Above
the bar graph the actual RS485-driver output level appears in
Volt. The minima and maxima values are stored right beside
the bar graph as a scale line symbol. The rotating slash
indicates the DP Slave actual measured. In the menu
Settings
(see Chapter 8.9) the duration of the single measuring can be
increased, which enables the measuring even of very slow DP
Slaves. Only the visible DP Slaves (max. 5) are measured. By
means of the
key the display window can shifted to
switch to the remaining DP Slaves. If in the menu
Settings
(see Chapter 8.9) Level scrolling is activated, the display
window is automatically shifted to display always the actual
measured DP Slaves, which guarantees a complete level
measurement with all selected DP Slaves. Any discrepancies
of the levels in comparison to the nominal range indicate
severe PROFIBUS network problems.
U < 2.5 V:
Weak level or no longer detectable.
2.5 - 7.2 V:
Level is ok.
U > 7.2 V:
If the indicated level is > 7.2 Volt, this is an
indication for a faulty power supply of the
Slaves or for reflections at the bus.
Summary of Contents for NetTEST II
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