Hello,

So as per my previous topic, in which I needed a PLC with 40 analog inputs.

Everyone suggested me to get a Simatic S7 but there are also various sub components in it.

So I am no experts at PLCs, I am still learning, on a LOGO PLC.

So I told my company's automation guy (on whom I have doubts) to get a quote from a Siemens distributor. And he got one for almost $7000 which is wayyyy too high. No one will buy the product we are making.

He's included a high speed CPU in it which I have no idea what would be use of it, all I am doing to do is connect about 32 analog inputs to it and send it's data over modbus to another computer. Maybe a few outputs to open actuators.

Does that really need a high speed CPU?

Doesn't the Simatic S7 have it's own CPU?

What is ET 200?

Should it really cost that high? If yes, then is there any other cost friendly option, other than a PLC?

 Hello Nitish_Patil;

Nitish_Patil

Hello,

So as per my previous topic, in which I needed a PLC with 40 analog inputs.

Everyone suggested me to get a Simatic S7 but there are also various sub components in it.

So I am no experts at PLCs, I am still learning, on a LOGO PLC.

So I told my company's automation guy (on whom I have doubts) to get a quote from a Siemens distributor. And he got one for almost $7000 which is wayyyy too high. No one will buy the product we are making.

He's included a high speed CPU in it which I have no idea what would be use of it, all I am doing to do is connect about 32 analog inputs to it and send it's data over modbus to another computer. Maybe a few outputs to open actuators.

Does that really need a high speed CPU?

- what is the model of this high-speed CPU? Normally, analog signal processing should not require very fast scan time on the CPU, temperature values for example e ol e slowly. Pressure and speed measurements change faster, but still do not generally need a very fast CPU. The requirements for high speed would have to be decided on the rest of the program, if you require heavy calculations on every cycle, for example.

Doesn't the Simatic S7 have it's own CPU?

- I do not understand what you need to know with this question. Please clarify.

What is ET 200?

- Siemens ET 200 are a family of remote I/O stations (Et 200M, Et 200S, ET 200X...) with different constructions and I/O modules. They are used to connect I/O cards on a network, Profibus-DP or Profinet. Some of these ET 200 stations offer their own models of CPUs that are often much cheaper (and less powerful) than their main counterparts.

Look at this presentation for more details:

https://new.siemens.com/global/en/products/automation/systems/industrial/io-systems.html

Should it really cost that high? If yes, then is there any other cost friendly option, other than a PLC?

-To discuss the possibility of a lower-cost solution that involves Siemens PLCs, talk to your nearest Siemens rep; you should really ask him to re-quote his offer, based on your financial and project requirements.. For solutions on other platforms, you could look at Advantec PC DAQ boards for example or similar proposals from other vendors. 

https://www.advantech.com/products/data-acquisition-(daq)-communication/sub_1-2mljza

Hope this helps,

Daniel Chartier 

Hello,

First off all we need to know what input types you need connect 0-10V or 0-20mA or 4-20mA or maybe RTD

Then I think I would put S7 -1200 CPU like 1214 or 1215 series it has 2 analog inputs 0-10V and then you can add extension modules to PLC (up to 8 extension modules)

so I found there are AI 8x13BIT extension modules 6ES7-231-4HF32-0XB0 and you would have up to 64 analog inputs

If you add AI4x16bit extension modules 6ES 231-5ND32-0XB0 you would have up to 32 analog inputs

All these extension modules configured and you have any off these inputs : 0-10V or 0-20mA or 4-20mA

and all amount with PLC with 8 extension modules will cost approximately about 3000 Eur.