servo motor on/off

hello dear friends.

i have read some ac servo manuals from different manufactures and most of them have told that "don't use servo on/off signal to start and stop servo motor frequently."

my question is:

what is the best way to start/stop ac servo motor?
Is it better to use setpoint(for example:give zero voltage to stop motor) and only use servo on signal in emergency conditions?

best regards.

I work with A-B so I can only comment on those. They have a stop command called MAS (Motion Axis Stop) that is used to stop movement.
They are different commands to start it moving such as the jog cammand (MAJ). You may want to tell us what servo you are using. This will let us be more specific.

thanks for your reply.

i usually use ac servo drive from teco(jsda series)and panasonic(minas a series).

best regards.

Generally, the On/Off or "Enable" signal commands the servo drive to hold its position. In essence it is a command to run at zero speed. If you try to manually move the motor shaft it will resist your efforts.

Quite often a servo drive will respond to an "enable" command with a "ready" signal. With some servo drives, if you issue a move command before the servo drive has signaled "ready", the drive will go into a fault state.

seee said:

hello dear friends.

i have read some ac servo manuals from different manufactures and most of them have told that "don't use servo on/off signal to start and stop servo motor frequently."

my question is:

what is the best way to start/stop ac servo motor?
Is it better to use setpoint(for example:give zero voltage to stop motor) and only use servo on signal in emergency conditions?

best regards.

Click to expand...

You are thinking all wrong about servos. They really don't 'start' or 'stop'. Start and Stop are terms from the velocity world.
With servos, you 'enable' the drive. Long before you 'enable' it, you set its mode (velocity follow, positon sync, etc.), so that, when it becomes enabled, it knows what to do.
After that, it just keeps doing whatever you told it to do, until it is no longer enabled.
To your question, which sounds like you're using the servo in a velocity mode, with an analog reference <(?)>...giving a zero volt signal will tell the servo to remain enabled, but be driving to 0 speed. The shaft will still have torque, which is, likely, the whole reason you used a servo in the first place.
If it follows a master, you could zero-out the master, or switch masters to a virtual master moving at zero.

In some applications we should start/stop servo motor frequently.
as far as i know it can be done with controlling analog setpoint and servo on/off signal too.some servo manuals tell that don't use servo on signal for on/off and other don't tell
anything.for example panasonic tell don't use.please see following manual.
http://industrial.panasonic.com/ww/i_e/25000/minas_a_e/minas_a_e.pdf