Starting/stopping torque, Parameter calculations - example, Current verification - example – Applied Motion ST10-C-CE User Manual

Page 86

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86

920-0025 Rev K

3/5/2015

CANopen User Manual

Starting/Stopping Torque

To start and stop motion, toggle the controlword halt bit (bit 8). When the halt bit is set to

0, motion will start or continue; when the halt bit is set to 1, motion will stop. The bit can be

toggled by writing 010F

h

and 000F

h

to controlword OD entry 6040

h

.

Parameter Calculations - Example

An application requires a torque of 50 oz-in. and a torque slope of 25 oz-in/sec. The motor

print lists the Torque Constant of the motor as 0.07Nm/A. The Nm/A constant given must first

be converted into mNm/A, as required by the Torque Constant OD entry. The formula used for

this is:


0.07

Nm

• 1000

mA

= 70

m • Nm

A A A

As the drive works primarily in Nm, the desired 50 oz-in of torque must also be converted

into Nm, using the conversion factor 141.6 oz-in/Nm.

50 oz-in

= 0.3531 Nm

141.6 oz-in

Nm

Now, the resultant torque of 0.3531Nm must be converted into mNm, as required by the

Target Torque OD entry.

0.3531 Nm • 1000 m•Nm = 353.1 m•Nm

Nm

The result is a value of 353 mNm, rounded to the nearest whole number, for the Target

Torque OD Entry.

Finally, the desired slope must be converted from the given units of oz-in/sec into the re-

quired units of mNm/sec.

(

25 oz-in

) * (

1 Nm

) * (

1000 m•Nm

)

= 176.55 m•Nm

sec

141.6 oz-in

1 Nm

sec

Rounding to the nearest whole number results in a Torque Slope of 177 mNm/sec.

Current Verification - Example

It is important to check that the current required of the drive is within the limits of the servo

amplifier. The drive being used, for example, has a continuous rating of 7 amps, and a peak

current of 14 amps, which may be held continuously for 2 seconds. This means that a current

of 7 amps can be held indefinitely, and currents between 7 and 14 amps may be used in short

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