Recent content by dickcaro

First, the term is INTEGRAL as in the calculus to integrate. If the integral term winds up, then this indicates that the process is NOT responding to your output of the manipulated variable. Whatever you are controlling, is NOT causing the temperature to respond. No amount of arithmetic will...

Nice try, but ISA publishes the Guide to the Automation Body of Knowledge (AutoBoK). It is a copyrighted work and sharing it over the Internet would be illegal. It is not available in PDF form anyway. The AutoBoK is the only book that contains the answers to the questions on the CAP Exam...

Obviously the signal conditioner is HART compatible. I suspect that you need to increase the loop resistance for the HART loops; a minimum resistance of 250 ohms is required for any HART circuit. You need to check that EACH 4-20ma loop has the minimum resistance.

Yes, with many VFDs internal programming will allow you to program this logical sequence. Not all VFDs are the same, so you will need to know which VFD is being used and then get the instruction manual from the VFD manufacturer. The pressure transmitter would be wired to the analog input...

There are no significant differences in cost among any of the DCS suppliers you named. All of them compete with each other. They are all easy to use, if you take their training programs, but they are different. Most of the users I know, use either Emerson DeltaV or Honeywell Experion. Dow...

Looking at the original problem description, it certainly appears that you experienced an electrical surge due to the lightning strike. It also appears that the transmitters are totally isolated from ground. Good wiring practice with 4-20mA instruments calls for shielded twisted-pair wiring...

Why in the world would you want to replace a DeltaV control system? With the information supplied, I would try to use the DeltaV and expand it where necessary. You do not indicate if this is a batch process, but I assume it is. Emerson has excellent batch software for the DeltaV. There is...

The quick answer is NO. Honeywell TDC 2000/3000 software was written for microprocessors that are very different from the microprocessors that can run Windows. Windows is not a real time operating system and is generally unsuited to run process control software, although it has been widely used...

Is the positioner actually attached to a control valve? If you are testing a positioner without actual valve position feedback, like any PI controller, it will drive to full scale 100% output..

It sounds like a continuing ground problem to me. Grounding only one end of a cable shield is fundamental. Remember that many FF multiconductor cables have both an overall shield and a shield for each H1 pair. <b>All shields should be grounded only at the power supply end, not in the field.</b>...

You certainly can control this process, but a PID controller is not the correct tool. PID is designed to control a process (pressure) at a steady state, which is not what you have described. You have described a batch process and a procedure that is designed for manual control. The result will...

If your VSD has an analog input, your flow transmitter's 4-20mA signal can be connected as the measurement signal for the PID controller in the VSD, and you do not need a separate PLC for this control loop. However, you will need a way to input the setpoint and the tuning constants for the PID...

I think you answered your own question - YES. All you need is to replace the pump 3-phase motor starter with a VFD sized for that pump motor. Leave the hand-wheel manual adjustment in the maximum flow position, and connect the PLC output (usually 4-20mA) to the VFD configured such that the...

A basic requirement for using this pump in a closed control loop is that you will need to be able to adjust its speed by the controller. You say that you now adjust this speed manually. You are missing an important piece of hardware: the actuator that can translate the controller output signal...

TDC 2000/3000 used a proprietary protocol created by Honeywell. You can find it fully described here: https://www.honeywellprocess.com/library/marketing/product-manuals/HG03-400.pdf. Before asking questions like this, please try to find your own answers the way I do - Google it! To find the...