lm629 missing encoder signal when enslavement is on

sidhoum yacine

Other Parts Discussed in Thread: LM629

we have some problem to detect missing signal encoder by using LM629N6 ,

does you have any solution to detect missing signal encoder in order to avoid to have pwm at 100% when encoder is disconnected ?

this problem occurs when the enslavement is on "no mouvement" when we disconnect the encoder the motor go at his maximum speed

does it have any software solution in order to veriffy encoder disconnection ?

Best regards

over 6 years ago

0 sidhoum yacine over 6 years ago

Prodigy 110 points

there is LM629 status register bit 5 used to detect error between real position and desired position does it be a solution to detect any problm sencoders signal ?

Best regards

0 Rick Duncan over 6 years ago in reply to sidhoum yacine

TI__Guru** 114905 points

Hi Sidhoum,

I am not very familiar with the device. Position error may work.

Do you have an encoder with index pulse? Is so, can you use the HI output as a watchdog?

The index pulse acquired interrupt flag may be the best choice if available.

Other options could be Read Real Velocity or Read Real Position and Breakpoint Reached interrupt.

0 sidhoum yacine over 6 years ago in reply to Rick Duncan

Prodigy 110 points

my system doesn't need index signal

does the LM629 have register that he can solve my problem when the motor is at enslavement position ,it dont mouve anyway over the reached position .

and also when the coder is deconnected ?

Best regads

0 Rick Duncan over 6 years ago in reply to sidhoum yacine

TI__Guru** 114905 points

Hi Sidhoum,

Assuming "enslavement position" means the motor is stalled, page 10 of the datasheet described how to use LPEI to detect a stalled motor.

Also there is the LPES command, that sets the motor drive to half-scale.

As mentioned, I am not very familiar with this device.

0 sidhoum yacine over 6 years ago in reply to Rick Duncan

Prodigy 110 points

thx for your reply we will work on it .

best regards

Motor drivers

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lm629 missing encoder signal when enslavement is on