4/11/2012 12:10 PM | |
Joined: 3/14/2008 Last visit: 12/10/2024 Posts: 2151 Rating: (966) |
I think this is a weird setup... What kind of process is this? Anyway, I assume you have an analog signal for the level sensor. You need a CTRL_PID where you connect the analog sensor signal to PV_IN.vThe "gain" parameter should be inverted (minus), so that the LMN parameter goes up when PV is getting closer to SP. The output (LMN) will be sent to the frequency drive having an output signal between 0 and 100. You may need to convert itto ahex value for the speed controller. You then create another CTRL_PID and you make a AND block for parameters LIOP_MAN and AUT_L. The AND block have input signals: IFSPEED PUMP=100%AND PV<>SP (process value is not equal to setpoint). The PID block is set to automode if the conditions are true. Then the LMN signal of the second PID should be connected to the second motor.. Make sure you have a hysteresis on the PV<>SP condition.... so that the control is more flexible..--> if the level is not between -5 or 5% of the setpoint, THEN themotor will be activated. |
Last edited by: Oreca at: 4/11/2012 12:10 PMIf I could help you, you can use the RATE button. Thank you. |
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