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1. parasitic parallel resistance path The RTD troubleshooting table at the link below is titled 'common' RTD problems and you'll note that there's no category for "lower than expected readings" because most RTD errors are "higher than expected" problems...

Any DCS I've been around required purchasing a license for the current version and maybe licenses for interim versions as well. Upgrades are the lifeblood of a DCS, a continuing revenue stream for the manufacturer. You need to check with Yokogawa.

Could be that a communication channel must be present or available for some action to proceed. Or a communication channel is disabled (interlocked) under certain conditions, probably to allow a higher priority communications channel to operate. Tough to tell out of context.

Somehow the measured voltage drop from the receiver AI's constant current source is lower than expected for two different receivers, the DCS and the temperature recorder. It is highly improbable that two receivers develop faulty constant current sources on their multi-input RTD AI's at the...

Congratulations on your entry into the world of systems integration. You need to determine what the burner controls do and how they work so that your PLC can be programmed to mimic manual control. For instance, is the start/stop button a sustained switch contact or a momentary contact? What...

It has to do with history. Early methods of Bernoulli based flow measurement involving a pressure drop across a orifice involved measuring the pressure drop with a U tube manometer. The manometer could be filled with mercury (Hg), water (H2O), even a liquid like alcohol or oil. Mercury is...

what style of construction is this multi RTD? Six individual RTD's each of a different length so that temperature is measured along the axis of the RTD? One set of wires (conductors), (2 or 3?) for each RTD? So there are 6 sets of wires coming out the end of the RTD assembly? Connection...

What is an SDM ? Check for continuity from either RTD lead to the sheath. If one of the RTDs is no longer insulated from the sheath and its elemnet is touching the protection sheath and the protection sheath is at a different potential than the current source return, then there will be a...

mrechtorik: Quite a list of issues. The first one, zero-based addressing vs one-based addressing is definitely a common issue. Your statement (2nd Complication): "Since Modbus only defines binary and 16-bit unsigned variables (sent as big-endian, i.e. higher byte first, then lower byte)...

Can you tell us what you did to get it working so that others can benefit from your experience?

Lots of authors, lots of articles out there, but I can't recall one that focuses on having the wrong valve characterization curve. But someone might pop up with a link. I have seen a couple cases that needed to change to equal percentage to prevent a linear characterized valve from hunting...

Since you say it 'start'-ed malfunctioning, and the valve can control to a steady state in manual mode, then something in the process has changed. Either find out what's changed and change it back or re-tune the process controller that drives the valve position to take into account the new...

From post #65 > you're reading half of the Real Power P1 value and half of the Real Power P2 value. Probably the only reason it's working is because the P1 and P2 values are either the same or very similar. This has come up a couple times in the past on this forum. The assessment is correct...

1. Getting the correct spelling of any device is critical in finding the documentation on that device. 2. General Observations about vendor documenation Glossy brochures are designed to make managers who can sign off a purchase feel good. Brochures rarely contain useable information...

Depending on who is master and who is slave there are some commercial protocol converters avaiable. Try searching for gateway protocol converter IEC 60870-5-103 and Modbus TCP

http://letmegooglethat.com/?q=calibrate+an+analog+pressure+transmitter

Some flow meters have a totalizer built-in and display a total. Some flow meters output a pulse ever X volume units (say, every 100L) and a counter can count the pulses to get a total. Some flow meters output a flow rate signal which is totalized by an external totalizesr.

Let us know how paralleling the contacts works. In all these years, I've never tried that. 'Snubbers' are used across the control relay contacts on inductive loads to absorb the back EMF that can arc and burn the relays. But the heater elements are not likely much of an inductive load...

"It's not the installers' or the commissioning personnel's responsibility to find and fix the problems of neglected maintenance and non-working equipment." As an installer/commissioner, I'll echo that statement. I've done recorder, data acquisition and SCADA projects, much smaller than a...

Maybe someone will show up here that can answer your question (I can't), but sometimes a manufacturer's forum can provide quicker and more focused answers. Siemens has a user forum named, Process Instrumentation / Analytics / Weighing Systems SIWAREX. Any Siemens forum requires registration...