Lenze MC3000 Series - Manual (Page 68)

64 13435743_EDBM301_v14 .0
70 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) .
74 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 .
75 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) .