[PPMAC Absolute Position Initialization Problem]

This could be a problem with the power-on PLC that initializes the ACC-14E. This may not be ready when your 'homez' PLC runs. Put a timer delay at the beginning of this PLC.

 

Forgive my ignorance, but will a "dwell" command work in this context?

[PPMAC Absolute Position Initialization Problem]

Note that it is not necessary to set these structure elements in your PLC:

Motor[n].pAbsPos

Motor[n].AbsPosFormat

Motor[n].AbsPosSF

Coord[n].PosRollOver[0]

 

as these are saved elements in Power PMAC. If you set these in your project and save them they will be permanent. Your PON PLC will be simpler. Also note that if bit 4 of Motor[x].PowerOnMode is set then this could be interfering with the homez commands your PLC.

 

steve.milici, thanks for your advice. Motor[x].PowerOnMode is set to 0 for both motor 1 and motor2.

[PPMAC Absolute Position Initialization Problem]

We are using an ACC-14E interface to a PPMAC to provide absolute position for two axes via synchro to digital (S/D) converters. When the PPMAC is first powered on, PLC1 is executed which performs a homez on both motor axes using the following code:

 

Motor[AZ_MOTOR_NUMBER].pAbsPos=ACC14E[0].DataReg[0].a

Motor[EL_MOTOR_NUMBER].pAbsPos=ACC14E[0].DataReg[3].a

Motor[AZ_MOTOR_NUMBER].AbsPosFormat=$00200F08;

Motor[EL_MOTOR_NUMBER].AbsPosFormat=$00200F08;

Motor[AZ_MOTOR_NUMBER].AbsPosSF=1.0;

Motor[EL_MOTOR_NUMBER].AbsPosSF=1.0;

 

Coord[1].PosRollOver[0]=360.0;

Coord[1].PosRollOver[0]=360.0;

 

homez AZ_MOTOR_NUMBER;

homez EL_MOTOR_NUMBER;

 

This routine correctly initializes the absolute position about 20% of the time. At other times, the position is exactly twice what it should be. When this occurs, acc14r0, acc14r1, acc14r3 and acc14r4 all contain the correct 16 bit angles; however #1p and #2p contain twice the angle, respectively. Re-running PLC1 from the IDE command line fixes the problem. I have attached before and after IDE screenshots of this.

[Tuning Tool Step Move Timeout]

When performing a two-way step move using the tuning tool (Position Interactive), the load moves the desired number of counts in the positive direction, stops, and fails to return to the initial position. The move then times out without a plot. When performing a one-way step move, the load moves the desired number of counts in the positive direction, stops, then the move times out without a plot. Can anyone explain this behavior?