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Moisture on the face of a transducer is a known problem with ultrasonics. The temperature of the air in the tank is below the dewpoint temperature of the relatively moist air over the water so water condenses. Some people tell me that applying a water repellent spray, like Rain-x, a...

> What do large EMS companies do when they have multiple devices from different companies to monitor? I'm just a one man show so I do it my way - I enter the slave ID number in the column next to the device's tag name in the spreadsheet. I even have a 'physical location' column. Seems to...

My memory of serial printers was that they needed flow control - small buffer memories and comparitively long execution times to empty the buffer onto paper (from quite some time ago). I haven't a clue how a serial/ethernet converter handles hardware flow control. Conversion to X-on X-off...

250 ohms is a low load value for an analog output. It only takes 5Vdc to drive 20mA through 250 ohms. If that's the active output capability of your AO, then, yes, that's why your positioner won't light up. 5Vdc < 9.7Vdc minimum required. The Load Power Supply ratings that you provided...

The Metso ND9000 spec says: Load voltage: up to 9.7 VDC/20 mA, (corresponding 485 ohms) So when you look at the PLC's analog output (AO) spec, you look for the load resistance that the AO can drive. Most active, powered, sourcing analog outputs will drive a loop resistance of at least...

>based on the FTDI chipset. I second the nomination of the FTDI chipset. Just today I installed a USB/RS-232 converter with an FTDI chipset on a Windows 7 box and it worked immediately, just like the others I've installed in the past 6 or 7 years. In contrast, last week a colleague got...

>based on the FTDI chipset. I second the nomination of the FTDI chipset. Just today I installed a USB/RS-232 converter with an FTDI chipset on a Windows 7 box and it worked immediately, just like the others I've installed in the past 6 or 7 years. In contrast, last week a colleague got...

Whoops, took a closer look. Correction to the diagram. Wiring should be 24Vdc (+) to Sensor (+) Sensor (-) to PLC (+) PLC (-) to 24Vdc (-)

You don't say which positioner you have. Some positioners have keypads and a menu. But if you have to use HART, this blurb http://issuu.com/rmcprocesscontrols/docs/dvc6200-fdt-brochure says Fisher's Fieldvue "digital valve controllers (positioners) with HART communications can be...

You should look up the part number on the relays that switch the RTD signal and make sure that the relays have gold plated contacts. The excitation current for an RTD is generally < 1mA, and such low currents require gold plated contacts. Any resistance added in an RTD circuit appears as a false...

Assuming that the symbols at the 24Vdc power supply are (+) and (-), what you drew is a classic circuit for 2 wire, loop powered instruments. So yes, if it's a 2 wire loop powered device, that'll work.

It isn't clear to me exactly what the problem, "all over the map" means (no examples provided). If the temperature drifts on the backup indicators but not on the controller and you believe the controller, then the indicators are not stable. If the indicator shows an offset from the...

OPC was originally promoted as an alternative to DDE, a Microsoft protocol for communicating with and populating an Excel spreadsheet. There are software packages that do talk to Excel through an OPC server. Depending on what your end goal is, you might investigate data acquisition software...

Sounds like a conventional pressure regulator to me, with the inherent proportional droop in flow rate as flow rate increases.

The idea is to - have two condensate pots, one for each impulse leg, at exactly the same elevation - have a constant level of water in each leg, so that at all flows, the head pressure of the liquid column in the impulse tubes will be equal, and therefore will contribute any pressure to either...

Electromechanical pressure switches need no power to operate, the line pressure on the sensor element activates the snap action electrical switch(es). Large elastomer diaphragms or bellows for lower pressures, metallic diaphragms or pistons for higher pressures. United Electric, SOR, Ashcroft...

Practical Distributed Control Systems (DCS) for Engineers and Technicians IDC Technologies. - 569 pages https://idc-online.com/content/distributed-control-systems-dcs-17 (take out any spaces the forum inserts into the URL) IDC Technologies offers courses, this might a text for their...

correction - gallon of water weighs 8.34 pounds

What about re-locating the bubble tube? $10 of plastic pipe . . . Did you correct for specific gravity? A 3-5 foot error on 20 foot tank is 15%-25%. Specific gravity could easily account for some of that error, if no such compensation has been applied. (To find the SG, go grab a gallon...

>1) How to Transfer the Data from Slave Device to other Slave device using Modbus TCP? A modbus master queries/polls a modbus slave with a message requesting data. The slave responsds with its data, or an error message. >2) does it use special software? The modbus master is...