S120, Basic positioner EPOS-slow!, CAM output

Hi,

How to increase the speed of the Basic positioner (EPOS)?

We need to position as fast as possible from 0 to 180 degrees

Using Sinamics S120, Basic positioner (EPOS).

We have a servo based on

• Sinamics S120 (PM240-2, 37kW) - 6SL3210-1PE26-0UL0
• Sinamics CU310-2 DP – 6SL3040-1LA00-0AA0
• COMPACT FLASH CARD FOR CU310-2 DP, U01: LICENSE DCB EXTENSION V 4.8 6SL3054-0EJ00-1BA0-Z U01
• Servomotor (20kW, Encoder AS24DQI) - 1FT7108-5SF70-1BA0

The drive is controlled by the PLC (Simatic S7-400) by Profibus (standard telegram 12x12).

We use the Basic positioner (EPOS), Program traversing blocks.

Two points:

+180 degrees (+5000 LU)

-180 degrees (-5000 LU)

EPOS settings are maximum:

Velocity 4 000 000 0 (1000 LU/min)

Acceleration 100 %

Deceleration 100 %

Position controller

P gain (servo gain factor) 8.0

With these settings, we measured the positioning speed

(through the IBA system)

And we received very bad results (for us)

(We need to position as quickly as possible from 0 to 180 degrees)

Measured positioning speed:

• The positioning time from 0 to 180 degrees was ~ 140ms (we need 50ms);

• The maximum speed in the positioning reached only ~ 400 rpm / min (the motor does not have time to accelerate to its nominal speed of 3000 rpm?)

How can we increase the speed of positioning?

We tried to increase the gain of the P gain (Position controller),

but after 8 starts a large problems of regulation (overshoot).

Hello,

in the first step I would do optimization of the drive.

With FW5.1 it is very easy by using OBT.

At that dynamic I would choose the torque precontrol too - so set p5271.4 = HIGH first.

Second I would set p5300 = 1

==> you would get an error, because you have to parametrize a distance for OBT - but in the ALARM window you would get the recommended distance.

You could parametrize in p5308.

Then do it again.

I saw in your parametrization that even the speed precontrol is not set to 100% at the position controller - but with OBT it would e set automatically :)

But: the EPos velocity is set to 30000 [LU//min] and a = 1000 [1000 LU/s²]

So a acceleration to vmax would need t = v/a = 30000 / (60 * 1000) s = 500ms.

Zako

zako_

Hello,

in the first step I would do optimization of the drive.

With FW5.1 it is very easy by using OBT.

now we have the version FW 4.8

6SL3054-0EJ00-1BA0-Z U01, do you think it makes sense to update FW until 5.1? 

can we do it ourselves? (and we have a license U1).

how do you think it's worth to increase P2574 EPOS jerk limiting 10 000 (1000 LU/s2)

Hi,

p2575 = 0 in your case . So you don´t have activated the jerk limiting.

Later you can activate it, but then set the jerk higer - for example 50 x higher then acceleration. Then you would get a jerk time of 20ms for example.

Zako

about updating firmware 4.8 -> 5.1

I did not understand how the license is transferred,

DCB Extension, order code U01

before the update I want to do make backup image CF card (Acronis), for safety!