Hi Guys,
I have a requirement to contol a pump speed with a VSD to achieve a steady temperature in a process environment. Hot water is being pumped and the actual temperature in the environment is measured and input via an analog card. The VSD is controlled via ethernet linked to the 1769-L32E Processor.
The setpoint temperature is operator controlled via HMI and ideally I would like to be able to vary the deadband too.
One final point is that if the tempertaure control loop wants to take the pump VSD below 25Hz, the VSD has to be switched off since that is the minimum speed for which the pump is rated.
Once the upper limit of the deadband is exceeded, the control loop would (hopefully!) command a frequency a few Hz above 25Hz such that the pump runs a decent amount of time rather than stop-start all the time.
I see the instruction set has a PID function, but I've not used it before so could do with some help please!
Many thanks in advance!
I have a requirement to contol a pump speed with a VSD to achieve a steady temperature in a process environment. Hot water is being pumped and the actual temperature in the environment is measured and input via an analog card. The VSD is controlled via ethernet linked to the 1769-L32E Processor.
The setpoint temperature is operator controlled via HMI and ideally I would like to be able to vary the deadband too.
One final point is that if the tempertaure control loop wants to take the pump VSD below 25Hz, the VSD has to be switched off since that is the minimum speed for which the pump is rated.
Once the upper limit of the deadband is exceeded, the control loop would (hopefully!) command a frequency a few Hz above 25Hz such that the pump runs a decent amount of time rather than stop-start all the time.
I see the instruction set has a PID function, but I've not used it before so could do with some help please!
Many thanks in advance!