rscott9399
Member
Hypothetical
You have an oil pump running.
You are reading a flow in GPM that is properly spanned from the device on a 4-20.
You need to add an additive to the flow. There is no flow meter on that additive so all you can do is turn the additive pump speed up and down with a 4-20 output. An operator will simply adjust on a 0 - 100% scale how fast the additive pump runs in relation to the flow.
The pump speed must be proportional to the flow.
I can do this easily with a bunch of compute statements and it turns into a math exercise.
Question : is simply doing the math the best option or is there an easy way to do it with a PID block in one rung?
any thoughts?
Thanks
You have an oil pump running.
You are reading a flow in GPM that is properly spanned from the device on a 4-20.
You need to add an additive to the flow. There is no flow meter on that additive so all you can do is turn the additive pump speed up and down with a 4-20 output. An operator will simply adjust on a 0 - 100% scale how fast the additive pump runs in relation to the flow.
The pump speed must be proportional to the flow.
I can do this easily with a bunch of compute statements and it turns into a math exercise.
Question : is simply doing the math the best option or is there an easy way to do it with a PID block in one rung?
any thoughts?
Thanks