Ok so a PID (block) is always giving 0-100% right? No matter what the set and the actual units are (degree Celsius in this case)
So if set = actual value = no error, the output is 0 right?
Then I could use the 0-100% output and scale it into 4-20mA on the analog 4-20mA output terminal.
I was...
Hi.
I have an application where i want to control the temperature in a room with a resistive load, Controlling the load with a PLC.
Ok so im going to use a powercontroller. The power controller takes 4-20mA and controls the load 0-100%. To be able to control the temerature due to a temperature...
Thanks for good suggestions.
I will go for PLC, Thermocuple, PID, and SCR. I'm using Beckhoff PLC. They have a autotuning PID for temperature control. I want to control temperature from the PLC as it is a part of a bigger building automation system and there is sentralized functions and...
Ok.
I cant drive big loads from a PLC, so I need a power controller. The PLC is used as a main controller in a distributed control system in house automation. So I found a way of doing this using PLC with I/O's, temperatur sensor and a SCR power controller. Controlling the temperature by a PID...
KNX or EIB is a bus system. It is often used in building automation on light and heat control. The components are very expensive but they have good functionality. So I try to find a way of controlling the heat without KNX devices.
Hi.
I like to control an electrical underfloor heating termostat with my PLC (Beckhoff). I like to be able to set setpoint (Temperature) and read flor temperature in the PLC
4-20ma or 0-10V is good, but also any bus signal is fine
However I cant find a sutible termostat for this job. Any...
Hi,
Anyone experience with Citect SCADA software. Im planning to use it in a building automation project. The vendor says it (CitectFacilities) is compleatly free. I find this hard to belive. It seems to be such a complex and powerful software. Is this true?
Is it a good software?
Thanks...
Hi.
I have an application where I going to control a servo motor. The input to servo motor driver card is +-10V. So I have a +-10V output card in my Beckhoff CX1030 controller.
The position of the servo is +-30degree, hence +-10V is +-30degree. The speed of the servo is given by frequency of...
Interesting that you mention this. It actually was for this purposes I had the initial question about the struct. It is part of such a state machine where states and transistions is compressed into a table. It is super efficient. The link you had describe a variant of the system I use.
I did...
Hi.
I try to implement an array of struct in IEC61131-3 ST language.
The C code look like this:
Code:
Struct BDD
{
Unsigned char a1;
Unsigned int a2;
Unsigned int a3;
Unsigned int a4;
}
struct BDD BDD_table[4] = {
{'X', 1, 1, 2},
{'a', 0, 100, 0},
{'a', 1, 100, 2},
{'X', 2, 5, 4}
};So...
Hi.
Im going to control a galvanometer (control of a mirror - set position (angle), set velocity, position feedback) with an analog driver board. The driver galvanometer is controlled like this:
analogue input (selectable +/-3, 5, 8 or 10V).
The position output is always +/-3V. Depending on...
Hi.
Im try to do a simulation. Its a complex assembly and I use automatically convert constraints to standard joint to save time. Now this is ok. However I like to delete some joints and change some welded groups but its not possible to delete or change anything. Why? Do I have to build...
Ok I agree.
But the range must be as wide as possible.
1. So will an zero-cross optically isolated triac driver work in, lets say 5-230 VAC , 0.5-120 Hz?
2. Do I need to filter the signal with other components to get a clean signal?
Hans
Thanks.
This is what I want exactly:
I want to make a cleen square puls from a 0 - 220VAC 0-120HZ. The signal must be noise free. The output (Square pulse) is going into a AVR microcontroller. Then I like to calculate the frequence of the AC signal.
The positiv part of the AC sine signal must...
I'v found something that I find interesting, a zero-cross optically isolated triac driver seems to take an AC signal into smal square pulses TTL signal, right?
