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You can measure waterlevel by measuring the pressure with a pressure sensor on the bottom of the vessel you want to measure. The more water there is in the vessel, the higher the pressure will be. We have a waterlevel sensor that automatically sends the measurements via the GSM network, see...

It -can- also be a hardware issue. If it is a short distance (1 meter or so) it is ok, but if you have more slave(s) a proper 120ohm impedance corrected cable with 120ohm terminator resistor might help. A normal 120ohm 1/8W resistor between the A and B line where the modbus ends will do. This is...

I always consider modbus one of the most easy to implement, reliable and: cheap interfaces to implement. And values are available for read/write on addresses. So its some kind of memory mapped IO, but then over RS-485 or ethernet connetion. Example: Values of data are stored on addresses and in...

We solved these kind of "problems" many times. We help many companies improve their temperature controls. PLCs are not that great in controlling temperature as a -real- separate PID controller does. We already improved many processes, by replacing the PLC PID control with our Japanese RKC...

No the temperature was just an example. With a fast response controller like the GZ you can also easily control pressure or flow. The principle remains the same as with temperature: measure process conditions (pressure & flow) as fast & correct as possible. Non-linearity is also that is solved...

The accuracy of the control is in my opinion how many % the measured value deviates from the setpoint, and how many deviations occur during actual control of the process per time unit. What is also very important, is how fast the controller reaches its setpoint from startup or when the setvalue...

Finding noise and solving these issues can be a daunting task. It is a matter of doing all the things as they should be emc-wise, so: 1) use Japanese electronics for the signal convertor. I have very very very good experience with Japanese electronics in combination with weak sensitive signals...

If you're not sure which wire is + or - you can check with a multimeter in mV range and holding a lighter under the tip. When you connect + and - correct the mV reading should go op. If you're not sure which specific thermocouple type you have (type E is a type, but for example J and K are also...

There are several possibilities to choose from: You can connect the Pt100 with 4 wire connection, the extra wires compensate for the resistance of the cabling. You can also consider a transmitter to 4-20mA, see for example these ones: https://cascade.net/en/transmitter/ Or you can switch over to...

Hi I work with lots of Pro-face 4201TAD screens daily. You can configure them for either modbus TCP master or slave. The IP address + subnet mask must be set in the offline menu of the screen (left-bottom right-top intermittent pusing until you can go offline). If you can tell me what you want...

Dear Kevin, This is a technical specification. That is the main mistake many people make. The customer is often not technical, for him you must write a functional specification in plain language that (almost) everybody without technical knowledge can understand. When both parties agree on the...

Also consider this SCADA software: SpecView. Combine it with a few modbus TCP (ethernet) digital/analog IO modules and you are good to go. Here are very rugged and reliable modules that I use a lot: https://cascade.net/en/modular-plcs/ And SpecView is very easy to program, it is specially...

What I normally do, is first make a good functional specification (what must the machine do and how) together with a process technologist that knows the product well and knows what has to be done with it and when. This must be in normal plain language, without automation-technical stuff that the...

You are right. A type T thermocouple is also what I would advise. It is more accurate (and stable) than a type K. We also have them calibrated so they come with a calibration certificate. Can of course be calibrated at the temperatures to your specification. A customer of mine uses them for...

I would implement modbus TCP (ethernet) for that. Most PLCs support modbus, or a communication interface can be installed for that kind of interface. Or at least a modbus RTU RS-485 interface.

I saw this problem quite often in cooking furnaces for butchers. We solved these problems by switching from the mechanically sensitive Pt100s to mechanically more rugged thermocouples, i.e. a type K thermocouple. But your measurement input must support that of course. I can assist you with the...

that's why I don't use windows for HMI/SCADA, it is not stable and changes itself with every update. I prefer Pro-face touchpanels running WxWorks/Windriver RTOS. That never hangs itself up and keeps on running. Problem with windows 10 is, that drivers get screwed up each time a new update...

depends on the device. Most Japanese devices, like our RKC instrument temperature controllers, don't need an earth.

Yeah, you know how many youngsters are these days............ They want to learn monkey-tricks. But they have to learn a way of logical thinking. The part of getting a functional description 100% right with the customer, is the most important part of all. They way of implementing that is just...

Normally you make a Modbus RTU interface with RS-485 a multi drop network. Does the communication work ok with only a few sensors (other ones disconnected) and start when adding more sensors 1 by 1 to the network. Maybe the interface cannot drive so many slaves and you need to add a RS-485...