Monday, January 04, 2016

PLC based PID Controller

Below is a Electrical Control Panel, It has a Strip Chart Recorder which is electro-mechanical, It has a PLC Inside. A handheld PLC Programming unit. The computer is showing the Ladder Logic Program. PLC is based on a embedded uC. The DIN Controllers are Analog + Digital circuits. So you see it is a Electrical Control Panel with Electronics and the PLC Ladder Logic means, Software too.

Process Control Application Notes

This is a PID Controller based Control Panel using a PLC from GE Fanuc Automation. The Computer is a 386 40MHz with 40MB HDD.

PID Controller PLC

Electrical Control Panel Wiring

Multizone Process Scanner

This could take current or voltage inputs from many remote transmitters, 4-20mA or 0-1 V Inputs. Then it would display the calibrated value in a LED display. The Zone number was a digital display. This serves as a monitor of process values. It had a analog output with a digital channel byte-word output for interface with other instruments.

This uses the CD4051-52 for the analog switching. Operating this at +/- 7.5V gives best isolation from channels and low ON resistance. Now you have many types of devices to do this.

Multizone Scanner

When a large area or object has to be heated, many heaters are used. This device can monitor and display the temperature at various points. The Operator then can make adjustments in heating or cooling so that he can maintain Uniform temperature or a Temperature Gradient as specified by the Process.

There are many ways, these scanners are used. Many different parameters like pressure, temperature, level are measured with different sensors and converted to a 4-20 mA level using transmitters for each sensor. Then many parameters can be measured in one equipment, when it needs only periodic attention. As the scan rate can be set from 1 to 50 seconds, the operator will be able to keep a tab on the values or record it. This reduces the real estate required on the control panel. Then the control room can be small, as it has to be at a vantage point, with a birds view of the entire factory floor.

Industrial Process Control Circuits

Sunday, January 03, 2016

Date Time Clock Widgets

I wanted to realize usability of controls within a small footprint. This lead to some innovations.
These are JavaScript and CSS Clock Widgets originally made for my webpage later improved and decorated for iGoogle. Now available as web widgets.

Date Time Clock Widgets

Date Time Clock Widgets

When i found the Remote controls and the early mobile phones difficult to use. I felt i have to try to design user interface within a small footprint. This helped me innovate a Active or Dynamic GUI concept; as shown in the Ability to change the skins of the Audio Music player and Digital Alarm Clock. The metronome too see the other project in this profile. These were done around 2005-6-7. Both for elements on my site and gadgets.

Digital and Analog Clocks


I also made a Virtual Web Gadget Alarm Clock Simulation that will demonstrate a Dynamic GUI in a Limited Facia Area.

Conclusions -

Reduce the number of operations a user would do at achieve a purpose. Auto, Intuitive, Context Gui. When a Customer comes to buy Trousers, Take him to the Trouser Corner. Do not show Tuxedo option. The colors have good contrast and the text clearly visible.

A Highlighted reaction to user action. Tactile. Dynamic GUI, see in Gadgets above. GUI Elements appear only for that sequence of actions. No clutter. Menus if used, should not get stuck. Should not be fidgety, should not be menus at all if possible.

Engineering, Interaction Design, UI/UX