Lenze MC1000 Series User Manual

Page 72

13435742_EDBM101_v24

Example: If D GAIN is programmed for 5 seconds, and the error is increasing

at 2% per second, the speed command output of the Differential term is

10% (5 x 2 = 10) of maximum speed.
NOTE: Differential gain is used as a “shock-absorber” to dampen overshoots in

fast-acting systems. However, it can be very sensitive to “noise” on the feedback

signal and to digitizing errors, so it must be used with caution.

PID ACC

(PID ACCEL/DECEL)

This parameter sets the acceleration and deceleration rate of the set point reference

into the PID unit. When the set point changes, this function will “filter” the input to the

PID unit by ramping the set point reference from the previous value to the new value.

This will help prevent overshoots that can occur when the PID control attempts to

respond to step changes in set point, resulting in smoother operation. If PID ACC

is set to 0.0 seconds, it is effectively disabled.

MIN ALRM

(PID MINIMUM ALARM)

This parameter setting represents the value that the feedback signal (in PID mode)

or speed reference signal (in open-loop speed mode) must fall below to activate the

MIN ALARM output (see Parameters 52, 53, and 54).

MAX ALRM

(PID MAXIMUM ALARM)

This parameter setting represents the value that the feedback signal (in PID mode)

or speed reference signal (in open-loop speed mode) must exceed to activate the

MAX ALARM output (see Parameters 52, 53, and 54).
NOTE 1: The MIN/MAX ALARM function can be used to start and stop the drive

based on the level of the speed reference signal or PID feedback signal. This is

done by wiring a 2-wire start/stop circuit through the drive's Form C relay or open-

collector output, and setting the Form C relay or open-collector output for MIN/MAX

(see Parameters 52, 53, and 54). When the signal drops below the MIN ALARM

setting, the relay or open-collector output will de-energize, which opens the start

contact and stops the drive. When the signal is equal to or greater than the MIN

ALARM setting, the relay or open-collector output will energize, which closes the

start contact and starts the drive. The drive must be in REMOTE mode to use the

MIN/MAX function to start and stop the drive.
NOTE 2: When using the MIN and MAX ALARM functions in open-loop speed

mode (PID is disabled), parameter 74 - PID FB must still be set to match the speed

reference signal being used.
98

LANGUAGE

(LANGUAGE SELECTION)

The MC Series drive can support other languages with the addition of an optional

LANGUAGE EEPROM chip installed in socket U11 on the control board of the

drive. If the EEPROM is not present, the default language will be ENGLISH. Also,

this parameter is not affected when the parameters are reset using Parameter 65

- PROGRAM. Therefore, if a language other than ENGLISH is selected, it will remain

in effect after a RESET.
99

FAULT HISTORY

The FAULT HISTORY stores the previous eight fault conditions that caused the drive

to trip. The information stored here is view-only, it cannot be altered. The FAULT

HISTORY can be used to determine if there is a pattern, or trend, to the faults, which

may indicate a problem in the system. Refer to Section 20 - TROUBLESHOOTING

for more information on faults.