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Ehh, you just told that you currently poll them with Modbus TCP, that is an ethernet connection, not a 3-wire RS-485 connection. That is another electrical interface and that is called Modbus RTU. Please check the documentation of your power meters if they (can) support Modbus RTU RS-485

yes, a thyristor with phase angle control will cut the sinus into a smaller part

O that is simple. Please use one of our thyristor modules for that. We have them with: - 1, 2 and 3 phase units - current from 10-2000 Amperes and above - voltage up to 690 Volts - with or without built- in or external super-fast fuses - heater-break alarm (for detection of broken or...

Is the valve linear? I mean, if you send a command for 25% flow rate, does the valve also open 25%? Many valves are non-linear or have an equipotential flow curves.

Can you please be a little more specific about this issue so we can help you better?

thank you for sharing!

I always use Lapp unitronic bus LD cable. 120ohm impedance corrected cable, specially suited for RS-485. Can be ordered by the meter at for example Conrad https://www.conrad.nl/nl/p/lapp-2170203-1-buskabel-unitronic-bus-1-x-2-x-0-22-mm-violet-per-meter-600095.html

4-20mA is a way more rugged signal and can be transmitted without sensibility to noise over long distances. You can also use a 4-20mA signal with DC voltage inputs, just put a resistor parallel to the signal at the DC voltage input to turn the stable 4-20mA signal into a DC voltage signal that...

Regarding the termination resistors of 120ohm. There should only be 1 at the end of the bus, where the bus stops. Not in between.

You could use a Pro-face GP4000 touchscreen. It can have both modbus rtu/tcp and a canbus interface. On the screen you can put the values and buttons for start/stop (for example). See: https://cascade.net/en/visualisation/

That is often the quickest solution.

Ok, better test it all very well with a good thermocouple simulator so you're 100% sure the measurement is correct to avoid misreadings. Especially with a high process value alarm you must be 100% sure about the correct measurement!

1) change the thermocouple in the process from B to K 2) use a -proper- temperature controller that supports all thermocouples, see: https://cascade.net/en/rb-series/

You have a metal tube, is it conductive? Can you measure a change in capacitance (nF) of the tube with/without the foam? Maybe it is a dielectric. You could test with a multimeter that can measure capacitance (many Fluke meters can do this). But for a more accurate measurement you need a proper...

I also use the simulation in Pro-face a lot. Last year I tested a few Weintek PLC and I must say: at first it looked impressive (especially the cMT-FHDX-820) but after the testing I had to use the smaller MT8050iE. When I started developing with that Weintek screen I immediately found that many...

1) are you sure the wheel is not slipping? 2) are you sure you are not missing pulses from the encoder in an noisy environment? Can you test it without noise (in workshop in small scale test setup for example? 3) do you "digitize" the encoder signal after a long length of cable? Or directly and...

? engineering makes practical use of things that have been developed by research. At least, that is how I see it.

What I always do and follow: below 10kHz only ground on the computer/plc/dcs side, above 10kHz: ground on both sides. At Philips we made a clean "measurement ground" inside the control panel and that is the point where we also connected the - of all power supplies to. Most frequency inverters...

That is true, I used Teledyne oxygen analysers and they had a 0-1V ouptput, this was always a pain in the #ss in noisy industrial environments.....

@WTF: very much so. Just had one on the phone that wasn't able to start his 4-20mA controlled burner...............I asked did you install the 500ohm resistor, answer: yesyesyes. Send me a picture and: tadaa. In series with the 4-20mA.....but it has to be between the + and - of the connection...