# Homework Help: Need Help With PLC's Assignment

1. Nov 16, 2006

### chriswall89@hotmail.

Here We Go. I have been asked to produce a program using GX Developer. The PLC i have to use is a Mitsubishi FX1N(C). I have to produce a program which will control a temperature sensitive fan heater in a hallway which leads to 2 adjacent rooms. The Heater and fan are designed to operate under the following conditions:

Input the temperature from the two rooms in degrees celsius.

Find the average temperature between both rooms

Contert the temperature into degrees fahrenheit

Compare the temperature to a preset value of 72 (+ or - 2.75%) so basically 70 - 74

If the temperature is below 70 degrees F, then the fan and heater will operate and a 1.5 second flashing alarm will be energised until the temperature is increased to its pre-set value.

If the temperature is above 74 degrees F, then the fan will operate and a 1 second flashing alarm will be energised until the temperature is increased to its pre-set value.

If the temperature is between 70 and 74 degrees F then the fan and heater should be switched off.

In addition, count the number of time the temperature has been outside of the pre-set range in a 2 hour (use 20 secs for this example). Indicate this ammount using BCD on the output display LED's
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I have already started this program but was unable to finish and i dont own a PLC or a copy of GX Developer at home and I no longer have any lesson time on this. I know it is abit too much to ask but try and think of it as a challenge or a brainteaser. Heres what i have so far i have no idea if this is right or wrong: http://i63.photobucket.com/albums/h137/chriswall89/PLCsAssignment.jpg
excuse the quality of this picture. I had to make the quality lower in order to upload the picture. If you need this then i will gladly email. If anyone does help either send me the file via email or post a picture of the ladder diagram please. Thanks in advance to anyone who helps or tries to help.

2. Nov 16, 2006

### chroot

Staff Emeritus
We will not do your homework for you. If you are stuck, please ask a clear, concise question indicating where you are stuck and your thoughts on how to proceed, and we will try to help you.

- Warren

3. Nov 16, 2006

### chriswall89@hotmail.

Ok sorry. Its not that im lazy and im asking other people to do this for me, I would love to do it myself if i had GX developer and a PLC because the only way to learn this is to try it yourself. But i have tried obviously to come up with the program but i cant tell where i am wrong or right without a PLC. If someone owns a PLC could they please try tell me where I am right, where I'm wrong and what else i need to do in order to finish the program.
Or better still does anyone know if i could get a virtual PLC on the computer and where to get 1 please. I reckon i could probably find a copy of GX Developer somewhere myself. Thanks In Advance.

4. Nov 16, 2006

### chroot

Staff Emeritus

- Warren

5. Nov 16, 2006

### chriswall89@hotmail.

That I dont know

6. Nov 16, 2006

### chroot

Staff Emeritus
If you're supposed to be using a tool that you don't have, you should really be speaking to your professor, not to us.

- Warren

7. Nov 16, 2006

### chriswall89@hotmail.

Ok I understand Thanks for you time anyway.

8. Nov 16, 2006

### Integral

Staff Emeritus
Beyond what Chroot says, I find your ladder diagram illegible. If it were legible and well commented we could at least try to verify your logic.

9. Nov 16, 2006

### chriswall89@hotmail.

Ok,l thanks for looking i think im just going to take chroot's advice and request more time from the lecturer.