This paper presents new device to simulate and inject a 4-20 mA current signal to PLC and control on this signal wirelessly. The proposed simulator device has been designed and implemented by a PIC 18f4520 microcontroller and an Ethernet click. This device is connected to Wireless Local Area Network (WLAN) via Wi-Fi router using TCP/IP protocol. The simulator has two channels for 4-20 mA current output signals with two channels for digital output signals, controlled by a laptop or a smart mobile. The purpose of this work is to demonstrate the usefulness of the Wi-Fi wireless technology for remote controlling on the 4-20 mA output current signal and the digital output signal in the designed simulator device. The experiments indicate that the proposed wireless simulator outputs the 4- 20 mA current with high accuracy and very fast response. The experiments also indicate that the proposed wireless simulator is easy, comfortable and convenient practically to use in the test operations of protections, interlocks and integrity of analog input channels for PLC compared to the wired simulator.
Nowadays, renewable energy is being used increasingly because of the global warming and destruction of the environment. Therefore, the studies are concentrating on gain of maximum power from this energy such as the solar energy. A sun tracker is device which rotates a photovoltaic (PV) panel to the sun to get the maximum power. Disturbances which are originated by passing the clouds are one of great challenges in design of the controller in addition to the losses power due to energy consumption in the motors and lifetime limitation of the sun tracker. In this paper, the neuro-fuzzy controller has been designed and implemented using Field Programmable Gate Array (FPGA) board for dual axis sun tracker based on optical sensors to orient the PV panel by two linear actuators. The experimental results reveal that proposed controller is more robust than fuzzy logic controller and proportional- integral (PI) controller since it has been trained offline using Matlab tool box to overcome those disturbances. The proposed controller can track the sun trajectory effectively, where the experimental results reveal that dual axis sun tracker power can collect 50.6% more daily power than fixed angle panel. Whilst one axis sun tracker power can collect 39.4 % more daily power than fixed angle panel. Hence, dual axis sun tracker can collect 8 % more daily power than one axis sun tracker .