Yaskawa iQpump Programming Manual - Manual (Page 25)

YASKAWA TM.iQp.02 iQpump Drive Programming Manual 25
Table 1 PI Setpoint Options
In some situations there are two feedback inputs. The drive can be programmed to maintain a set differential between two analog signals.
If input A2 is configured as a “PI Differential Mode” (H3-09 = “16: PI Differential”), then the iQpump drive will maintain a set
difference between the measurements read on inputs A1 and A2. This differential setpoint is programmed by parameter (b5-07).
■
b5-01 PI Mode
The iQpump drive can be used as a stand-alone PI controller. If PI functionality is selected by parameter b5-01, the iQpump drive will
adjust its output to cause the feedback from a transmitter to match the PI setpoint (b5-19). The setting of b5-01 will determine whether PI
functionality is disabled (b5-01 = “0: Disabled”), enabled (b5-01 = “1: Enabled”), or enable with the output of the PI function used to
trim a Speed Command (b5-01 = “3: Fref+PI”).
■
b5-02 Proportional Gain Setting
Setting Range: 0.00 to 25.00
Factory Default: 2.00
The proportional gain will apply a straight multiplier to the calculated difference (error) between the PI Setpoint and the measured
transmitter feedback at terminal A2. A large value will tend to reduce the error but may cause instability (oscillations) if too high. A small
value may allow to much offset between the setpoint and feedback (See Figure 22 on following page).
■ b5-03 Integral Time Setting
Setting Range: 0.0 to 360.0 sec
Factory Default: 5.0 sec
The Integral factor of PI functionality is a time-based gain that can be used to eliminate the error (difference between the setpoint and
feedback at steady state). The smaller the Integral Time set into b5-03, the more aggressive the Integral factor will be. To turn off the
Integral Time, set b5-03 = 0.00.
The PI Setpoint will be read from:
If these conditions are true
Status of b5-18=
Status of Modbus Register
0Fh bit 1
Status of b1-01=
Parameter b5-19 1 N/A N/A
Modbus Register 06H 0 ON N/A
D1-01 0 OFF 0
Terminal A1 0 OFF 1
Serial Comm. 0 OFF 2
Option PCB 0 OFF 3
Setting Description
0 Disabled (factory default)
1 Enabled
2 Fref+PI