Brake management

[lchianella]

We found a strange reaction of the Brake management in PPMAC.

 

Use of ouput 2 of Acc11e for Brake:

Motor[1].pBrakeOut = Sys.piom+$A0000C

Motor[1].BrakeOutBit = 8 +1;

Motor[1].BrakeOffDelay = 1000; // en msec.

Motor[1].BrakeOnDelay = 1000; // en msec.

 

Brake management OK on these conditions:

#1out0 or #1J/ --> output ON (brake OFF) + amp enable out ON

#1dkill or AmpFault --> output OFF (brake ON) + amp enable out OFF

 

For some reasons, when motor is killed, we want to generate an Amp Fault by, for example, putting "Motor[1].AmpFaultLevel=1"

 

Status motor gives correct "ampFault =true".

 

I this case, if we do #1out0 -->

Amp Enable output stays OFF (normal as Amp Fault), but the output goes ON (brake OFF).

 

Is this normal?

[curtwilson]

We are looking into this. However, it is not a standard operation to change the amp fault polarity in this manner.

[AnthonyLH]

Is there something new on the automatic brake-control function? I also had some issue with brakes, see below.

 

M_Sys_IO_DO_Drive_ResetError=1 // Drive reset

// Wait some sec

M_Sys_IO_DO_Drive_ResetError=0

&1 enable // It switchs to AmpEna==1 and it removes the brakes: ok

&1 disable // It switchs to AmpEna==0 and it put on the brakes: ok

&1 enable // It switchs to AmpEna==1 and it removes the brakes: ok

// Here I do an emergency stop (whitch remove power on drives) : AmpEna==0 , brake are on, AmpFault==1 : ok

// I put back power on drives but I do not reset the drives, AmpFault is still ==1

&1 enable // AmpFault==1 but anyway the brakes are removed !!!

[curtwilson]

We have never been able to duplicate this, in either scenario. Reviewing our internal logic, which has not changed, we do not see how this could happen. When the motor is enabled, it checks for a fault condition on the next RTI. If it sees it in fault condition, it disables the motor again. It does not matter if the brake was released before or after this - the brake ends up engaged.

 

We will keep investigating.