4inONE – 4to20mA signal generator


4inOne is a 4-20 ma current loop signal generator is a troubleshooting and a training tool for instrumentation works. This box using Bluetooth to communicate with Android app.





  • Comm: Bluetooth
  • Source:4-20 mA
  • Loop power: 24 Vdc 42mA
  • 3 mode pattern generator for sourcing: 1.Square wave 2.Triangle wave 3.Sawtooth wave.
  • Autographic plotting and data logging in txt format.
  • Power: rechargeable NimH 2.4 Vdc
  • App: Android RF4to20



Customized HMI panel

Chemical Tanks HMI
GSM Remote Alarm and Warning monitoring system


SLC500 Allen Bradley Training Module


ldmicro (LDMICRO)arduinoplc


How it works:
This PLC board is actually an Arduino Nano shield, which is able to accept and drive  24 VDC Inputs/Outputs.
The  free Ladder program (see  LDMICRO)  is used to write logic diagrams. For this example, a  blink.ld  is  created  and will be compiled as a  blink.cpp  file. From the blink.cpp  file, we create a header file (blink.h) and put them together in the Arduino library. The next step is to write a sketch on the Arduino IDE and to  put #include <blink.h> on the first line. Analog inputs/outputs, HDMI/LCD interfaces and Modbus communication can be done on an Arduino sketch. We have already written several example programs, ladder diagrams and sketches to simulate real applications.

Board specifications:

CPU socket: Arduino nano
Operating voltage: 24 VDC
I/O: Optoisolated 8 inputs/outputs. Any I/O can be configured as input or output by
moving opto to another socket.
Output current continuous load: 150 mA
Communication:  two-wire RS485 (Modbus protocol can be implemented using the Modbus library on the Arduino sketch).



How it works:

X10 home automation has been around for many years, and it’s very popular due to easy installation and maintenance. X10 utilizes your house’s power lines  to send and receive signals, so no more wires are needed to install the basic X10 system. With the popularity of cellphone texting message services we offer the X10 modem, which has the capability of receiving and sending X10 signals from and to any cellphone anywhere. The X10 GSM  modem utilizes GSM networks. In the United States,  AT&T and T-Mobile offer prepaid plans as low as $20/month for unlimited texting. They will provide a SIM card, which has to be activated before use with an X10 modem. To receive X10 data, we can use any cellphone regardless of the network; it can be Verizon, Sprint, Metro PCS, AT&T or T-Mobile.

(see  X10 diagram) When an X10 wireless motion detector such as MS16A detects a moving object, it will send X10 radio signals to the X10 transceiver (TM755), assuming that MS16A has already been set/programmed as House code A, Unit code 4.
The signal propagates through power lines and is then received by a Powerlinc 2413S serial interface, then converted to serial data  to the X10 GSM   modem. The X10  serial data decoded by the modem then will be transmitted using SMS/texting services. The recipient will see “A*4_ON” on his/her phone.
To activate an X10 module such as AM466 (for example, if it was programmed as House code A and Unit code 7) we send the following text: A7TON). This command will be received by the X10 GSM modem and converted to standard X10 signals by 2413S, then distributed throughout power lines. This signal will activate a relay inside the AM466 module to turn on a light bulb.