catman®Professional: Auto Command list for Min/Max recognition

For actuator testing, the force/displacement characteristic is measured over n load cycles. The task to be performed by the measuring chain including force and displacement transducer, Spider8 and catman32 was to display the individual load cycles online and to save the maximum force together with the associated displacement.

If an actuator enters its load limit, it starts "slipping" and the force characteristic drops. The motor control detects the maximum force and downs the actuator to zero position if "slipping" is recognized. After a predefined cool-off time a new test cycle has been started again.

The catman® Measurement Wizard has been set to Periodic measurement.

The individual measuring cycles have been triggered via the catman® trigger function (F> xN).

Bearing play and lubrication properties had a decisive effect on the actuator’s performance. Long-term tests of more than 1000 cycles have shown verifiable changes in the max. nominal load.

The below Auto Command list has been used, the first section must be executed upon start-up, the second one after each measurement
period.

1.
VARIABLE M1 M2 M3 M4 M5 -> Declaration of the variables
DB[5].Export = 1 -> Select database channels for export
DB[6].Export = 1
DB[7].Export = 1
M5 = 1 -> Set period counter to 1
EXPORT.Filename = "C:\Daten\Motor.dat" -> Specify file name and path for export
EXPORT.Format = 1 -> Select "Binary" as export format

2.
M2 = DB[2].Max -> Write force maximum into variable M2
M4 = DB[2].Maxindex -> Determine position of the maximum force
M1 = DB[1].Row[M4].Value -> Write associated time into variable M1
M3 = DB[3].Row[M4].Value -> Write associated displacement into variable M3
DB[5].Row[M5].Value = M1 -> Write force, displacement and time into DB channels
DB[6].Row[M5].Value = M2
DB[7].Row[M5].Value = M3
EXPORT.Execute -> Export selected database channels
M5 = M5 + 1 -> Increase counter value (next measurement)