DAQ Card Interfacing- Controlling Home I/O using External Devices
Step 1: Understanding the Elements
Objective: DAQ CARD INTERFACING- Controlling Home I/O using External Devices
Starting Conditions: Home I/O is being controlled by Inbuilt Sensors
- Door Detector 1 (Bit 78)
- Door Detector 2 (Bit 79)
- Motion Detector (Bit 258)
- Alarm Keypad- Armed (Bit 82)
Output: Siren (Bit 58)
Connect I/O Functions to be used
- SR- SET RESET
Step 2: Wiring Diagram With USB 4704 DAQ Card I/O Solutions:
We have connected Push Button NO & NC to the Digital Input of DAQ Card as shown below. IN0 is Normally closed switch, such that, it TURN ON the DI0 if not pressed, on being pressed it TURN OFF DI0. Whereas IN1 is push button Normally Open, which TURN ON DI1 when pressed, else it DI1 is OFF.
DI Output are configured to give LOW signal (O VDC) when Turned ON. In DI0 ~ DI2 we have connected LED’s with Series resistance (220 Ohm). When signal at DI0 ~ DI3 goes high, the respective LED goes ON. The Positive side of LED is given 5VDC from the DAQ Card.
Step 3: Connect I/O Solutions
Step 4: Function Used: Source Bit
Source Bit: This is an ON/OFF bit used to give TRUE/FALSE Signal to Logical gates. When you
press it once, it goes to TRUE & when you press is again it goes to FALSE
Bit 193: Entrance Gate (Open): This is the standardized bit used to open the Entrance gate
Bit 194: Entrance Gate (Close): This is the standardized bit used to close the Entrance gate
BIT 260: Entrance gate (Opened): This bit gives feedback for the Gate 1. When Gate 1 is fully opened, it gets ON else its OFF.
BIT 261: Entrance gate (Closed): This bit gives feedback for the Gate 1. When Gate 1 is fully closed, it gets ON else its OFF.
Step 5: Description of Functions Used
2 Input OR Function: This function gives TRUE (or HIGH) output when either or both of its Input (IN1 & IN2) are TRUE. If both of the inputs are false, Output is false.
Boolean Expression: OUT1 = IN1 + IN2
NOT Function: This function gives TRUE output when Input is False. If inputs is false, Output is TRUE.It is also known as “Inverse” Function
Boolean Expression: OUT1 = IN1
SR: SET- RESET BLOCK:
This block is used to Latch/Unlatch the output such that, on receiving the pulse at SET- It will hold the Out Terminal permanently, until it receives Pulse at RESET. This is SET dominant function, which means, if Input is applied to both SET & RESET Terminal, this function unlike RS block will SET the output
Step 6: Explanation of Solutions:
DAQ CARD INTERFACING- Controlling Home I/O using External Devices
Following are the two Objectives which we need to achieve in this activity
TO OPEN/CLOSE THE GATE USING EXTERNAL PUSH BUTTONS NORMALLY OPEN IN1 & IN2:
On pressing External Switch IN1 we have latched the “Entrance Gate Open Bit 193” to open the door. This bit is unlatched using “Entrance Gate Opened Bit 260”.
Such that, gate opens when IN1 is pressed & get close automatically when 100% opened.
Similarly Gate get closed when IN2 is pressed which latched “Entrance Gate Close Bit 194” until it closed 100%. So when IN2 is pressed Gate started closing & by feedback bit “Entrance Gate Closed” the “Entrance Close Bit 194” get unlatched
To read the Feedback of Gate in External LED’s such that:
- When Gate is Closed – RED LED should be ON
“Entrance Gate Closed Bit 261” is used as a feedback to TURN ON DO2 which gives 0VDC signal to the RED LED Connected to the DAQ Card DO2 terminal.
Hence, when Gate is Closed this Bit 261 turns ON the RED LED.
- When Gate is Open – GREEN LED should be ON
“Entrance Gate Opened Bit 260” is used as a feedback to TURN ON DO0 which gives 0VDC signal to the GREEN LED Connected to the DAQ Card DO0 terminal.
Hence, when Gate is Opened this Bit 260 turns ON the GREEN LED.
- When Gate is Moving- Yellow LED should be ON
This is a situation when none of the Bit 260 & 261 is ON, which indicates Gate is neither closed nor opened, it’s moving. To highlight this state we have given the Bit 260 & Bit 261 signal to NOR Gate, which gives TRUE/HIGH Output only if NONE of the input is ON.
Hence, the objective is achieved, and we have Yellow LED ON when the Door is moving. This cycle can be repeat again & again.
Check out the Video Demonstration: https://www.youtube.com/watch?v=lmQEtIJhFjQ
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