Rockwell Automation SA500 Drive Configuration and Programming User Manual

Page 55

Configuring the UDC Module’s Registers

3-23

3.4

Volatile Gain Registers (Registers 150-199/1150-1199)

The Command Register view is used to configure the volatile gain registers. These
registers are used for volatile gain data sent to the PMI by the UDC module. This data
is sent to the PMI asynchronously and is only transmitted when a gain value is
changed.

The values in these registers, including changes made on-line, will be lost when power
is removed. At power-up, register default values will be active. Default values must be
initialized by the application task. These values must be within the pre-defined limits
set by the UDC operating system. If a volatile gain value is out of range, bit 10 of
register 203/1203 will be set.

Note that the volatile gain values are updated at a rate equal to the UDC scan rate
times the number of gain values (17). For example, if the UDC scan rate is 10 msec.
and there are 17 gain values, then the update time is equal to 10 msec. x 17 = 170
msec.

3.4.1 Speed Loop Gain Variables

Speed Loop Crossover Frequency Register

150/1150

This value in this register is the crossover frequency of the PMI speed
loop. It specifies the time required to reach the desired motor speed
and adjusts the overall gain of the speed loop. The value (in rad/sec)
is scaled times 10, i.e., a value of 10 rad/sec is entered as 100.

Sug. Var. Name:

WCOS%

Sug. Def. Value:

100

Low Limit:

High Limit:

10000

Step:

Speed Loop Damping Factor Register

151/1151

The value in this register is the damping factor which provides
independent control of the speed loop’s integral gain. Refer to
appendix C for more information. The value is scaled times 100 so
that a value of 0.7 is entered as 70.

Sug. Var. Name:

ZETAS%

Sug. Def. Value:

Low Limit:

High Limit:

800

Step:

Speed Loop Rate Limit Register

152/1152

The PMI speed loop uses the value in this register to limit the speed
reference value's rate of change.

The value is entered as the number of external velocity unit counts
(register 105/1105) per second divided by 10 so that a rate of 12370
counts per second is entered as 1237.

Sug. Var. Name:

SPD_RATE%

Sug. Def. Value:

3276

Low Limit:

High Limit:

3276

Step:

Speed Loop Feedforward Register

153/1153

The value in this register controls the amount of inertia compensation
that is fed forward to the torque loop. It is entered as a percentage
(0-300%). If J_BAR% and J_SCALE% are entered correctly, a value
of 100 will correctly compensate for total reflected inertia.

Sug. Var. Name:

SPD_FF%

Sug. Def. Value:

100

Low Limit:

High Limit:

300

Step: