Lenze MC3000 Series User Manual

Page 68

13435743_EDBM301_v14 .0

PID MODE

(PID MODE SELECT)

This parameter activates the PID function, and selects whether the PID control will be

direct or reverse acting . Refer to Section 19 - MC3000 PID SETPOINT CONTROL . The

following options are available:

OFF

Disables the PID function to allow “standard” drive operation .

NORMAL

Enables the PID function for direct acting systems . An increase

in the feedback variable will cause a decrease in motor speed .

REVERSE

Enables the PID function for reverse acting systems . An increase

in the feedback variable will cause an increase in motor speed .

NOTE:

The REVERSE selection is not used to compensate for reverse acting

feedback devices . If a reverse acting feedback device is used, program

Parameters 75 and 76 - FB @ MIN and FB @ MAX as described in Section

19 .1 - FEEDBACk DEVICES .

When PID is enabled, and the drive is in REMOTE and AUTO mode, the drive will operate

in a CLOSED LOOP fashion, responding to the feedback signal in order to maintain the

process setpoint . In this case, the setpoint reference can be a 0-10 VDC or 4-20 mA

signal, or the keypad . The SPEED REFERENCE SOURCE indication in the CONTROL

display will indicate VDC (0-10 VDC), IDC (4-20 mA), or AkB (keypad), depending on

the setpoint reference .
When PID is enabled, and the drive is in LOCAL and AUTO mode, the drive will also

operate in a CLOSED LOOP fashion . However, in this case, the only setpoint reference

available is the keypad, and the SPEED REFERENCE SOURCE indication in the

CONTROL display will indicate AkB .
When PID is enabled, and the drive is in MANUAL and LOCAL or REMOTE mode, the

drive will operate in an OPEN LOOP fashion, responding directly to speed commands

from the keypad only . The SPEED REFERENCE SOURCE indication in the CONTROL

display will indicate MkB .
When PID is disabled, the drive will operate in an OPEN LOOP mode, responding directly

to speed commands from either the keypad (MANUAL mode) or an analog input signal

(AUTO mode) .

PID FB

(PID FEEDBACk SOURCE)

This parameter selects the terminal to be used for the feedback signal, and can be set

to TB-5A or TB-5B . TB-5A is used for 0-10 VDC signals, and TB-5B is used for 4-20

mA signals .
NOTE:

The MC3000 has only one analog input of each type, so the same type of

signal cannot be used for feedback and setpoint reference . For example, a

4-20 mA signal from a transducer could not be used as a feedback signal if

the setpoint is being controlled by a 4-20 mA signal from a PLC .

FB @ MIN

(MINIMUM FEEDBACk VALUE)

This parameter should be set to the value of the process variable that corresponds to the

minimum transducer feedback signal (0 VDC or 4 mA) .