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AKD EtherCAT Scaling for Velocity, Acceleration, and Deceleration

This article discusses AKD EtherCAT scaling for velocity, acceleration, and deceleration commands and actual velocity.  For the position modes, FBUS.PARAM05 applies to position scaling and the scaling for velocity, acceleration, and deceleration.

PP = Profile Position
IP = Interpolated Position
CSP = Cyclic Synchronous Position
PV = Profile Velocity

The following tables list the AKD parameters/objects that define the scaling for velocity, acceleration, and deceleration.

  • Object 6081h = Velocity command
  • Object 60FFh = Velocity command
  • Object 6083h = Acceleration command
  • Object 6084h = Deceleration command
  • Object 606Ch = Velocity Actual Value

 

PP mode:

FBUS.PARAM05 bits 6081h PDO 6081h SDO
Bit4=0, Bit9=0 UNIT.PIN/s (UNIT.PIN/UNIT.POUT)/s
Bit4=0, Bit9=1 (512) UNIT.PIN/s UNIT.PIN/s
Bit4=1, Bit9=0 (16) (6092h/6091h)/s (6092h/6091h)/s
Bit4=1, Bit9=1 (528) (6092h/6091h)/s (6092h/6091h)/s
FBUS.PARAM05 bits 6083h PDO 6083h SDO 6084h PDO 6084h SDO
Bit4=0, Bit9=0 UNIT.PIN/s^2 (UNIT.PIN/UNIT.POUT)/s^2 UNIT.PIN/s^2 (UNIT.PIN/UNIT.POUT)/s^2
Bit4=0, Bit9=1 (512) UNIT.PIN/s^2 UNIT.PIN/s^2 UNIT.PIN/s^2 UNIT.PIN/s^2
Bit4=1, Bit9=0 (16) (6092h/6091h)/s^2 (6092h/6091h)/s^2 (6092h/6091h)/s^2 (6092h/6091h)/s^2
Bit4=1, Bit9=1 (528) (6092h/6091h)/s^2 (6092h/6091h)/s^2 (6092h/6091h)/s^2 (6092h/6091h)/s^2

Note: SDO values are rounded, so they may not match PDO values exactly.

Note: DS402 scaling defined by 6092h/6091h is actually:

  • 1 gearbox rev = (6092h sub 1 / 6092h sub2) / (6091h sub 1 / 6091h sub2), or
  • 1 gearbox rev = (6092h sub 1 * 6091h sub2) / (6091h sub 1 * 6092h sub2)

 

CSP, IP modes:

6081h: Does not apply

6083h: Does not apply

6084h: Does not apply

Velocity, acceleration, and deceleration are handled in the master controller’s motion profile generator.  They are the result of the target position setpoints interpolated at the PDO update rate.

The master profile generator calculates the target position data points over time that will generate the desired motion profile.

 

PV mode:

FBUS.PARAM05 bits 60FFh PDO / SDO
Bit4=0 RPM * 1000
Bit4=1 RPM
FBUS.PARAM05 bits 6083h, 6084h PDO 6083h, 6084h SDO
Bit4=0 RPM/s * 1000 RPM/s * 1000 (rounded)
Bit4=1 RPS/s RPS/s (rounded)

Note: These are independent of Workbench units.

Note: FBUS.PARAM05 Bit 9 has no effect on these objects.

 

All modes:

(Tested in IP, PP, PV modes.)

FBUS.PARAM05 bits 606Ch PDO 606Ch SDO
Bit4=0, Bit9=0 RPM * 1000

IP mode: N/A

PP, PV modes: Workbench Units

Bit4=0, Bit9=1 (512) RPM * 1000

Workbench Velocity Units:

RPM

RPS

Degrees/s

(UNIT.PIN/UNIT.POUT)/s

Radians/s

Bit4=1, Bit9=0 (16) RPM RPM
Bit4=1, Bit9=1 (528) RPM RPM

 

 

Default Values:

  • Default value of FBUS.PARAM05 = 0 (Bit4=0, Bit9=0).
  • Default values of 6091h and 6092h subindexes 1 and 2 all =1, so these need to be set appropriately for the mechanical system.  Set these using SDO's or drive parameters.