Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual - Manual (Page 16)

16 Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011
Chapter 1 Detailed Drive Operation
Analog Input Loss Detection
Signal loss detection can be enabled for each analog input. Parameters 1093, 1094
and 1095 [Anlg In
xLossCnfg] control whether signal loss detection is enabled
for each input and defines what action the drive will take when loss of any analog
input signal occurs. One of the selections for reaction to signal loss is a drive fault,
which will stop the drive. All other choices make it possible for the input signal to
return to a usable level while the drive is still running.
If the input is in current mode, 4 mA is the normal minimum usable input value.
Any value below 3.2 mA will be interpreted by the drive as a signal loss, and a
value of 3.8 mA will be required on the input in order for the signal loss condition
to end.
If the input is in unipolar voltage mode, 2V is the normal minimum usable input
value. Any value below 1.6V will be interpreted by the drive as a signal loss, and a
value of 1.9V will be required on the input in order for the signal loss condition to
end. No signal loss detection is possible while an input is in bipolar voltage mode.
The signal loss condition will never occur even if signal loss detection is enabled.
Value Action on Signal Loss
0 Disabled (default)
1 Fault
2 Hold Input - (continue to use last frequency command
3 Set Input Lo - use parameter 30 [Min Spd Ref Lim] as frequency command
4 Set Input Hi – use parameter 31 [Max Spd Ref Lim] as frequency command
5 Goto Preset1 – use parameter 14 [Preset Speed 1] as frequency command
6 Hold OutFreq - maintain last output frequency
4 mA
3.8 mA
3.2 mA
Signal Loss
Condition
End Signal Loss
Condition
2V
1.9V
1.6V
Signal Loss
Condition
End Signal Loss
Condition