Yaskawa iQpump Drive User Manual - Manual (Page 99)

5.1 iQpump Basic Programming Parameters
YASKAWA TM.iQp.01 iQpump Drive User Manual 99
Table 5.1 PI Setpoint Options
In some situations there are two feedback inputs. The iQpump 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 Setting
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 5.16 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
3 Fref+PI