Rockwell Automation FlexPak 3000 Digital DC Drive Version 4.3 - Manual (Page 73)

Configuring the Current Minor Loop 6-3
6.2 Selecting and Conditioning CML Reference Selection
A hardware jumper, J15, configures the drive as a current/torque or speed/voltage
regulator. When J15 is set to
CURRENT , the input signal TORQUE REFERENCE (P.189) is
the CML reference. TORQUE REFERENCE can come from an analog input, frequency
input, or a network master. When J15 is set to SPEED , the signal SPD LOOP OUTPUT
(P.299) is the CML reference. The software reads the setting of hardware jumper J15
only at powerup. See the hardware manual for information on setting jumpers.
The selected CML reference passes through an amplitude limit block and a rate limit
block. See figure 6.1 for the block diagram.
The amplitude limit block prevents the reference signal from becoming greater than or
less than the limits selected by
CML REF LIMIT SELECT (P.311). These limits can be
either the values set by parameters NEGATIVE CURRENT LIM (P.006) and POSITIVE
CURRENT LIM (P.005), or the limit values being used by the speed loop PI block.
The rate limit block limits the rate of change of the selected CML reference based on
value you input for CML REF RATE LIMIT (P.303). CML REF RATE LIMIT (P.303) defines the
minimum allowable time (in milliseconds) that the reference can change from zero to
MAXIMUM CURRENT (P.007). When the drive is stopped, the output of the rate limit block
is clamped to zero. The amplitude and rate-limited CML reference appears as the
output parameter CML REFERENCE (P.396).
NORMALIZED INERTIA
(P.222)
The time required to
accelerate the motor
and load inertia from
zero to motor base
speed at
MOTOR
RATED ARM VOLTS
(P.009) and MOTOR
HOT FLD AMPS (P.510).
Parameter Range: 0.05 to 65.20 seconds
Default Setting: 1.00 second
Parameter Type: Tunable
OIM Menu Path(s): Speed/Voltage Loop (SPD) - Speed/Voltage Loop
(SPD) Tuning
This parameter is set by the speed loop self-tuning procedure. You can also enter it
directly. Self-tuning will overwrite values entered manually.
CML REF LIMIT SELECT
(P.311)
Selects the source for
the
CML positive and
negative current
limits.
Parameter Range: 1 = SPD LOOP PI LIMITS
2 = REGISTER
Default Setting: 1
Parameter Type: Configurable
OIM Menu Path(s): Additional Parameters (listed by parameter number)
If you select REGISTER , the CML loop limits are POSITIVE CURRENT LIM (P.005) and
NEGATIVE CURRENT LIM (P.006).
If you select SPD LOOP PI LIMITS , the CML loop reference limits are the same as those
used by the speed loop PI block.