₦airaland Forum

@Emmasoft, please throw more light on dollar mutual fund.
Thanks

freeman67:
Funding of dollar mutual fund account right now is not a very easy process except, the CBN relaxes the rules or you look for a mutual fund that will do the exchange for you at their own rate.

Can't somebody get dollar from Aboki and paid into dollar fund account?

I would like @Rawsh55 , my runaway class rep @Southboy, and other serious students to upgrade to this level.
The picture below is an input from Uzoma Awaka.
You can have millions of correct answers to my assignment above, that's why it's logic

Uzoma maybe a guest on Nairaland, if so, please try to register to make things easier for us. He has some advance tools which others can learn from

Good input from Uzoma Awaka. May I know your nairaland username

Rawsh55:
@Mentor

What’s the way forward.. we can’t afford to stop here

If we have 5 to 10 active students, then we progress.

All those interested in the training should indicate by doing the assignment. You must not get it right, what matters most is making an attempt.
That's only way of learning here. Reading alone without active participation cannot take you anywhere.

Very good input from Rasheed Sanni. May I know your Nairaland user name.

You must learn to develop and task your brain. This is a must for prospective Automation experts. This is a mentorship class.

Only one person responded to my assignment. Where are others?

Southboy:
@ Lecturer sir, please consider our request for the sake of those that are interested.

Am always a busy person. My schedule is always tight. The truth is that you can't learn the course without active participation. It's only a reasonable active persons that can draw my time and energy to this training.
If the training is constrained to limited individuals, the aim is defeated.

Meanwhile, write a ladder logic program that involves two NO and two NC inputs with only a coil as output.
Let see how serious you guys are. Send your work to aniobinnaeee@yahoo.com

More inputs before we advance

nnewsnjobs:
Well understood.

Please can you explain how the system will work if there many people going in, say they are on the line or que going into the hotel, how would the outside and the inside sensor respond since at every time someone will be outside and another one inside, because they are on a line/que, just thinking! Thanks

Good question.
This is where logic comes in. The example above is to illustrate the concept of sensors and contacts. In actual design, many things come into play like emergency conditions, time to lock the gate, detecting suspicious object/weapons from individuals, crowd of people trooping in etc.
We are not talking about design at the moment, our attention is only to explain types of contacts and what actually represent contacts in the real life. As we advance in this training, we are going to task our brains on different possibilities (Logic)

Bright12660:
Please boss, can this knowledge and principle be applied to something as large as a gate? Thanks

Why not, once you have a good logic behind it, it can be translated to reality.

In automation, we can group the system into three major units
a, Field devices (sensing devices)
b. Actuators ( action devices eg motors)
c. Program (written instructions)

The signals from the field devices form the input to the PLC while the output from the PLC acts on the actuators.
The output depends on the written logic programs.
Now let's illustrate with this example.
I entered into a hotel named Park inn in saint Petersburg Russia, the main entrance door immediately opened on it's own without human assistance, it closed the moment I entered inside. I have not experience this in Nigeria, maybe such system might exist, I don't know.
Let's explain the automatic door.
It has two sensors, one at the outside, the second position inside. These two sensors are referred as contacts inside the logic program. The door also has a motor(actuator) that open and close it.
Motor action is dependent on the output signal from the PLC.
Let's call the first sensor input A and the second sensor input B.
The moment you stand in front of the door, the sensor detects your presence and send a 24vdc signal to the PLC, the input A/Contact is activated and the coil( output) is energized, the door opens.
The moment you enter inside, the input B/Contact is activated, thereby resetting the coil(output), the door returns back(closed)
Many confusions, feel free to ask your questions.

Please refer to the ladder diagram above.
You will notice two colours; green and black. The two colours shows that the user is on online mode. When offline, the entire diagram turns black.
The diagram looks like a climbing ladder hence the name ladder logic.
There is a special computer design by the PLC manufacturer for programming, this computer is called PG (programmer). The PG (Laptop) is very expensive and may cost above #15m.

When there is a problem on the line( many machines put together) that could not be solved by operators, electricians, mechanics, engineers on duty, the next point of call will be the automation guy. You're expected to login your PG to find out the fault.
The moment you go online, you see the signal flow on the PLC. The signal flows from the left side to the right side. The inputs are positioned on the left while output on the right.
The green color indicate the signal while the black color indicate where the signal flow stopped.
Any confusion or questions at this point

ytdivine:
Ladder Logic programming.
Consider the diagram below
We have entered into programming
What do understand from this logic program?
I stop here until I get minimum of 5 inputs from my students

Let's explain the ladder diagram

I nominate @doghorp as assistant course rep to support @southboy in moving the class forward. @southboy has been performing excellently in advancing the group. Two is better than one as stated in the Bible

I have noted all the suggestions and will act on them. All we have been doing is background work, if you have followed up to this point, you will definitely catch up as we enter deep into the program gradually.
I will post videos to illustrate certain points only when am satisfied by the number of followers to justify the time and energy in creating such practical videos.
I have gained this uncommon knowledge and want to pass it across, all I need is seriousness and commitments.
I want to say it again, the training is free

chadbaby:
Continue pls, we are following silently

You can't understand this program without very active participation, the reason why I view it as waste of my precious time and energy.
Even my powerful course rep @southboy said he has lost memory of some things discussed, that shows lack of assimilation.
Please let only the serious guys indicate their interest not the silent followers

If I have about 4 more serious people like you, I will continue. Am not interested in being paid. The class is free. My time is very precious to me

This class is free, reason people don't value it.

I come in the moment everybody is ready. I can't continue if the class is not active

danielukwuru:
I'm interested

You're welcome

BOLA625:
I am interested.

You're welcomed

doghorp:
The vertical line are power lines
The Horizontal lines are called rung or network
The Input are always connected on the left side of the Rung while the output are always connected on the right hand side of the Rung.
Power flow from left to right on the rung the flow of electricity will stop because the system is in NO (Normally Open contact) state.
The circuit shows that the logic program INPUT is in NO (Normally open) in other words the system is not energized. The output in the first rung is called -(S)- Set Coil while the output in the second Rung is called -(R)- Reset coil.

Nice input. Remaining 4 inputs before I explain the diagram

If you don't have any idea just indicate

Ladder Logic programming.
Consider the diagram below
We have entered into programming
What do understand from this logic program?
I stop here until I get minimum of 5 inputs from my students

The major confusion student normally have is this normally open and normally closed contacts issues.
The best way to understand it is by testing a relay with multiple NC and NO.
This will form our practical number 3.
Please class rep take note.

nnewsnjobs:
@Op, I can see that you are very knowledgeable in what you are doing, many people will not really understand the worth of the knowledge you are giving here for free. God bless you richly for what you are doing.

Will it be possible for me to contact you for industrial support/contract work in the field of automation if the need arises in the company were I work?
I myself am electrical engr. but I only get little knowledge of automation through self learning.

Thanks for the prayers.
It's quite unfortunate that the young graduates don't know the value of what am doing. I don't blame them because they lack the necessary exposure. Am doing this for conscience sake. Am already retired from field work having worked for over 15years.
However, I can provide technical support and in-house training depending on the time and location.
My own business borders on industrial electronics supply import and export. I have a network of friends across the globe for any industrial needs. aniobinnaeee@yahoo..com.

My primary concern is to raise young automation engineers that can take over the space occupied by the foreign expatriates in Nigeria

Study the symbols below used in Ladder Logic Programming

Input: Contact (whether NC or NO)
Output: Coil
Box contains the program

Southboy:

bestbiz17
Kingslaw
mosho2good
zealousayo
Akinzola
southboy
Jokolly
thedarkened
newusername
smartphil
eddyboy
bright12660
doghorp
cleardway4me
Username of everyone that has signified interest to join the class

Only active members will be given Automaton materials as gift

Southboy:

bestbiz17
Kingslaw
mosho2good
zealousayo
Akinzola
southboy
Jokolly
thedarkened
newusername
smartphil
eddyboy
bright12660
doghorp
cleardway4me
Username of everyone that has signified interest to join the class

Good job

While we wait for others to respond, let consider the relay circuit.
Relay consists of two parts:
a. Coil
b. Contacts
When DC current is applied to the coil, the soft iron core becomes a magnet (Electromagnet) and attract the armature bar to it, closing the air gap. The Contact C changes state.
Contact is made up of two types
I. Normally Closed (NC)
ii. Normally Open (NO)
When the coil is energized, the NC becomes open and NO becomes closed
and vice versa when de-energized.

The change of States by the contacts is utilized in logic design while the coil being energized or de-energized is optimized in control.
In summary, the coil is used to control the states of the contacts

doghorp:
When the coil is energized it produces a magnetic field. This magnetic field attracts the armature (movable contact). When the coil is de-energized the coil loose magnetic field and a spring retract the armature to its normal position.

Good job.
More inputs