Hi.
I'm designing a system with an integrated SM23165DT and I was wondering if I could get some guidance on best practices for integrating the motor with an emergency stop circuit.
Is getting the motor with the DE option always best?
If I don't have a DE option motor and don't care about maintaining position during an E-stop, but want to interrupt power, what's the best way?
Should I interrupt the DC motor power? I think I read that this was a bad practice with SmartMotors.
If I interrupt the AC to my power supply, there is a lot of residual energy remaining in the system before the motor stops. Should I also switch in a power resistor on the DC side of the motor in this case to bring the motor to a quick halt?
Thanks for the help anyone has to offer.
Jeff.
Hi Jeff,
The -DE option is always best to have. If you don't have it, you usually have to re-home.
In either case, the easiest way to interrupt power is on the AC side of the power supply. If you have a problem with the motor still moving as the power drops out, you can use an I/O on the motor to detect that the E-Stop was pushed, and halt motion(you can program an interrupt for this).
If you need to break power on the DC side, you need to have a Shunt wired in the circuit, so that the Shunt stays with the motor, not the power supply.
If you have a high inertia load or rapid starts and stops, the Shunt is a good idea even if you are breaking power on the AC side(just to protect the motor from it's own BEMF).
-Chuck
I am using the -DE option.
I need to query the motor periodically to see whether or not the eStop has been pressed.
I am having a bit of difficulty getting this to work.
Is my best bet to use the command PRINT(Bo,#13) and just loop that? I've noticed that the Smartmotor playground recognizes the eStop event (and release) instantly but this is not the case for when I try to do it programmatically.
I cannot find an example code for this.
Any help appreciated!
-Graham
RUJA will return the bus voltage(48000 would represent 48VDC). If it's a Class5 motor, you can also check status bits. Bit 13 of Status Word 6 is Low Bus Voltage. You can check that bit with RB(6,13). Either one will let you know the Drive Power is off.
Hi all !
Is someone can provides me an example on how to program a Halt Motion into an interrupt ? I need to stop the motor when the emergency stop is pressed.
Thanks !
Hi all !
Is someone can provides me an example on how to program a Halt Motion into an interrupt ? I need to stop the motor when the emergency stop is pressed.
Thanks
Hi MaxLim4507.
Take a look at the Moog Animatics SmartMotor™ Developer's Guide under the section entitled "Interrupt Programming" for me it was on page 177 of the version revised: 08/24/2015.
It has an excellent explanation of how to use interrupts, including an example. Using the example, for your application you would need to change the interrupt configuration to react to a digital input channel (status word 16, the bit and state of your E-stop input signal). The interrupt subroutine is already configured to halt the motor.
There are additional code examples in each of the related command definition sections of the manual (ITR, EITR, ITRE).
Hope this helps.