Servo JOG mode vs Speed Control mode

[Luke.S]

If you just want to run a Mitsubishi rotary servo at a constant speed does it make any difference if you use the JOG command or put it into speed control mode? Or to put it another way; is there any reason you should <u>not<\u> use jog mode for routine operation?

 

Say you have 8 servos in a line that you just want to run at a very low, accurate speed, simply putting 8 JOG FBs in the program would save a lot of time.

You can change the speed even in JOG operation with the speed change command. The drive must be controlling the torque in the same way to achieve steady velocity as in speed control mode unless you are limiting torque or something. So what's the difference?

[JRoss]

I don't think there is a functional difference between a Jog and a Speed Control mode for something as simple as that.

[joynal.eee59]

On 7/27/2016 at 7:44 AM, JRoss said:

I don't think there is a functional difference between a Jog and a Speed Control mode for something as simple as that.

Dear Mr. JRoss,

I've an application to run a servo continuously & it'll not be stopped until i give stop command. Is it technically ok, if i use Jog operation? Is there any limitation of jog operation?

I'm using mitsubishi FX PLC & MR-J3 drive. Expecting earlier response, thanks in advance :)

[JRoss]

I think the only difference is that in jog mode you don't have control over the speed using digital inputs or analog input. I would use speed control mode in your application for that reason.

[joynal.eee59]

18 hours ago, JRoss said:

I think the only difference is that in jog mode you don't have control over the speed using digital inputs or analog input. I would use speed control mode in your application for that reason.

It's possible to change jog speed anytime from HMI but my confusion is about will servo motor be rotating continuously untill i give stop command in jog mode? In fx series, maximum output pulse is 100k !! Another question, is it possible to change speed from HMI for speed control mode? as far i know, speed value can be changed only by setting drive parameter. Waiting for your valuable response :)

[joynal.eee59]

22 hours ago, joynal.eee59 said:

It's possible to change jog speed anytime from HMI but my confusion is about will servo motor be rotating continuously untill i give stop command in jog mode? In fx series, maximum output pulse is 100k !! Another question, is it possible to change speed from HMI for speed control mode? as far i know, speed value can be changed only by setting drive parameter. Waiting for your valuable response :)

Dear Mr. JRoss,

I'll be very happy, if you please share PLC program instruction (with data register for speed set) for speed control mode in FX mitsubishi. My application is to change the speed from HMI when needed & servo will rotate continuously, FYI, i did program for position control mode both inc and abs. Thanks in advance :)

Regards,

Joynal, Automation Engineer, Bangladesh.