ALSPA PROFIBUS Field Bus Coupler Appendix A.Configuration Example
(09/06)
Technical Manual
Page A9
on a loss of the PROFIBUS link. Setting parameter P75.07 to a 1
does this.
If this value is set to 0 then on a PROFIBUS loss the reference
value will be frozen. This means that the last valid value received
over the link will be used.
Note:
ALL PROFIBUS reference/control values are affected by
the freeze/fallback simultaneously.
The fallback values can now be entered for the relevant PROFIBUS
reference, for the speed reference we will use a fallback value of 0.
If communication is lost then we would like the drive to stop, this
means that the start control flag should be set to 0, and the stop bit
should be set to 0. This means the fallback value should be 0000H.
These settings are summarised in Table A-13.
Table A-13 Fallback value example
Param
Value
Meaning
P75.07
1
On PROFIBUS loss use the fallback
not the freeze value
P75.13
0
PROFIBUS reference 1 (speed
reference) fallback value
P75.09
0000H
PROFIBUS control word 1 (start/stop
flags) fallback value.
Bit 0 - Not set, stop flag active
Bit 1 - Not set, start flag inactive
Bits 2 - 15 – not required
A.13
Warning on Loss of PROFIBUS Link
This function is carried out by P75.06 (described in Section 7.4.8).
During the commissioning process P75.06 is set to 1 by default, and
the drive generates a Warning. When commissioning has been
successfully completed, P75.06 may be set to either :
0 = Ignore loss
1 = Warn of loss
2 = Trip the drive
