selection of PLC

Hi,I am kamlesh from india.
I am doing project on PLC in TATA MOTORS.I want to choose PLC having 35 inputs and 12 outputs.
But,This PLC must be cost effective.
On which site I get simulator of PLC FOR PROGRAMMING
(download free)
[email protected]

Just stating the number of I/O is not enough, you must describe the functionality to determine the amount of processing required and any specific timing requirements.

Hi,

You can use any lower version PLC's from Siemens (S7-200), AB (Micrologix) or GE Micro PLC with additional IO card DI card. Cheapest will be Automation Direct PLC for simple operation.

Hello kamleshgaikwad.

Tata Motors is a big company that probably allready use PLCs in many places. Before you go for just any low-cost PLC I suggest you investigate which PLCs are allready in use at Tata, and then chose one of them.
There can be reasons for picking a new PLC that has not been used before at a site, but "lowest cost" is not one of them.

Agree with JesperMP.
Very seldom a PLC brand choice is a technical issue and almost always- a political one.

Picking PLc's

Just a friendly reminder. Someone other than yourself will be working on that system. If it is different from every other PLC in the plant your "Cheaper" just went out the window. Remeber PLC's come with all kinds of expensive parts. When you change brands all of these items have to be purchased all over again. So when calculating what PLC to use here are the items I look at.

1)Familarity- Are the guys who will be working on this machine familar with this processor
2) Training cost- How much does it cost to get training on this platform.
3)Interface cost- what is the cost of cabling and software. how hard is the interface to use
4) Avability of PLC- is this PLC already obsolette, how well does the manufactor support the PLC


After those 4 main issues I then look into the process items, scan time, I/O's etc.


Basically, The point I am trying to get across is the the CPU is a part of the equasion not the whole thing.

selecting a PLC

Hey stating only number of inputs and outputs is not enough for selecting the PLC brand.
The details of the application or the process for which you are using plc is very important.
You should take note of following points while you are selecting the plc :
the power supply to be used, the number of digitaland analogue inputs and outputs including the signals for analogue ones i.e voltage current etc., the response time for the PID control loop, scan rate available and then ofcourse the cost.

kamleshgaikwad said:

Hi,I am kamlesh from india.
I am doing project on PLC in TATA MOTORS.I want to choose PLC having 35 inputs and 12 outputs.
But,This PLC must be cost effective.
On which site I get simulator of PLC FOR PROGRAMMING
(download free)
[email protected]

Click to expand...

Hi,
Now a days all the PLCs are not very expensive. Therefore you can go for any PLC. However, Siemens and Allen Bradley are the most common PLCs in India. Also, think about standardisation. Check which PLC is being used in Tata motors. It must be usin a lot of PLCs.
Regards,
Ramesh Walia