Setting up my own practice rig

Hi guys, I recently attended my first Siemens training course and i really enjoyed it. The only issue i have now is i probably won't get near a PLC until i attend the next course. So i have decided to setup my own s7-300 rig so i don't forget everything i've learnt.

I'm going to set up a PLC and profibus network to run a micromaster 420 and motor, Simatic touch screen and possibly a small conveyor if i can get my hands on one and attach the relevant sensors etc.

My question is just regarding the hardware at the moment, I can use a 313-2 dp cpu or a pre 2002 315-dp cpu any particular reason why i should go for one over the other?

I'm looking at getting a cheaper PSU rather than paying for a more expensive Siemens model apart from it converting 230v-24v is there anything else i need to consider?

https://cache.industry.siemens.com/dl/files/906/12996906/att_70325/v1/s7300_cpu_31xc_and_cpu_31x_manual_en-US_en-US.pdf

The above link is the S7-300 CPU 31xC and CPU 31x: Technical specifications

I would review this before deciding on the CPU to purchase.
Regards,
Garry
http://www.accautomation.ca

rob63 said:

Hi guys, I recently attended my first Siemens training course and i really enjoyed it. The only issue i have now is i probably won't get near a PLC until i attend the next course. So i have decided to setup my own s7-300 rig so i don't forget everything i've learnt.

Click to expand...

Congrats!

rob63 said:

I'm going to set up a PLC and profibus network to run a micromaster 420 and motor, Simatic touch screen and possibly a small conveyor if i can get my hands on one and attach the relevant sensors etc.

Click to expand...

Any particular reason you've chosen that hardware? Micromasters and S7-300's are the old Siemens platforms, they have newer drive and PLC families now. If it's what you expect your employer to want you to know, or you already have some of the HW, then go for it. If you're starting from scratch, though, you might want to start learning on the newer stuff. It really depends on what you are trying to learn.

rob63 said:

My question is just regarding the hardware at the moment, I can use a 313-2 dp cpu or a pre 2002 315-dp cpu any particular reason why i should go for one over the other?

Click to expand...

Not sure there. The smaller CPU's like the 313 typically come with IO built in, which may help you. If it is a 313C, then that is the compact version, which includes some IO. I've never seen a 315C, so you usually have to buy IO modules separate.

rob63 said:

I'm looking at getting a cheaper PSU rather than paying for a more expensive Siemens model apart from it converting 230v-24v is there anything else i need to consider?

Click to expand...

In theory, any 24V power supply should work fine. In an industrial environment, more expensive power supplies can offer extra features like diagnostics, battery backup, higher efficiency, better voltage control, etc. In practice, for your personal lab, just about any 24V source will probably do, as long as it has the correct capacity and input voltage.

mk42 said:

Congrats!



Any particular reason you've chosen that hardware? Micromasters and S7-300's are the old Siemens platforms, they have newer drive and PLC families now. If it's what you expect your employer to want you to know, or you already have some of the HW, then go for it. If you're starting from scratch, though, you might want to start learning on the newer stuff. It really depends on what you are trying to learn.



Not sure there. The smaller CPU's like the 313 typically come with IO built in, which may help you. If it is a 313C, then that is the compact version, which includes some IO. I've never seen a 315C, so you usually have to buy IO modules separate.


In theory, any 24V power supply should work fine. In an industrial environment, more expensive power supplies can offer extra features like diagnostics, battery backup, higher efficiency, better voltage control, etc. In practice, for your personal lab, just about any 24V source will probably do, as long as it has the correct capacity and input voltage.

Click to expand...

Hi, yes we have the s7-300 on site so they put me on the serv1 course which focuses on the 300/400 series. So i guess this is where i should carry on from.

On the course we used a 315-2 dp however it was the newer version, i can't afford to buy this version though, so i'm looking at the pre 2002 is there any difference apart from physical size? i can see the newer version uses a sd style memory card, not too sure what the older version is using?

i can't find any info for either model in the pdf posted above??

S7 300 CPU 313 2 DP 6ES7 313 6CE00 0AB0

or

S7 300 315 2DP 6ES7 315 2AF03 0AB0

quick update.

I've retrieved the project i was working on during the course and purchased the same cpu

CPU PLC 315-2DP 6ES7 315-2AG10-0AB0

i just need to find a data sheet for the tech specs so i can match up a psu and suitable memory card

The Siemens support site is the best place to find tech specs, manuals, etc. The link below is already searching for your part number.

https://support.industry.siemens.com/cs/products?pid=93169&mlfb=6ES7315-2AG10-0AB0&lc=en-US

Rob, don't forget the special memory card (MMC). the series 300 CPU's don't work without them. 512kB will be OK: 6ES7953-8LJ20-0AA0

I bought this last night;

SIEMENS SIMATIC Memory Card 64 KB 6ES7 953-8LF20-0AA0

Worried that isn't the correct size now, doh!!

This is an Old CPU:
Siemens 6ES7315-2AG10-0AB0, S7-300 CPU315-2DP 24VDC, 128 KB Working Memory
The new cpu 6ES7315-2AH14-0AB0 has 256kB.

You should never buy a MMC smaller than the CPU memory.

The MMC is essentially the hard drive of the PLC, so if it is smaller than your work memory it will function, but you'll just be limiting how much you can do. I would think that for a simple training setup 64k should be OK if you've already ordered it.

Nonuke is correct though, you should typically buy an MMC bigger than your work memory.

Thanks for the information, guess i missed that on the course. Whilst we are talking about memory, i would just like to see if i understand how it operates with you guys.

The program is loaded onto the mmc and executed from here. It is not saved directly within the PLC memory. If i remove the memory card whilst it's in Run mode the PLC will crash.
When performing a memory reset on the 300 the mmc is not affected. However on the 400 everything is erased?

You are correct. The S7-400 doesn't need an external memory to run.

rob63 said:

The program is loaded onto the mmc and executed from here.

Click to expand...

Correct

rob63 said:

It is not saved directly within the PLC memory.

Click to expand...

Also correct. When the PLC boots up, it copies everything in load memory to work memory, and then sets all the M/I/Q to 0 (except retentive values).

rob63 said:

If i remove the memory card whilst it's in Run mode the PLC will crash.

Click to expand...

Some programs might keep running from work memory, but either way, you're right, don't do it. It's bad for the MMC, and it definitely isn't recommended.

rob63 said:

When performing a memory reset on the 300 the mmc is not affected.

Click to expand...

Yes. A memory reset is basically the same thing as the PLC getting powered on. The Work memory is deleted, and then the project is copied off of the load memory again. This means that all DB values get set to their initial value, and all M/I/Q memory goes to 0.

rob63 said:

However on the 400 everything is erased?

Click to expand...

Not sure about the 400. I know it does have at least a little bit of internal load memory and does not require a memory card, but I know it also has a few different kinds of memory cards to expand the load memory. they may react differently to a memory reset. I know at least one kind of S7 400 memory card is flash memory, which mostly behaves like the MMC for the 300.

Cheers, thanks so much for your help, really glad I found this forum

I have been on the lookout for a PSU i came across this

http://uk.rs-online.com/web/p/din-rail-panel-mount-power-supplies/7767722/

my CPU

https://support.industry.siemens.com/cs/pd/93169?pdti=td&lc=en-US

The output load is rated at 2.5A. The 315-2dp can draw a maximum of 2.5A do i need something with a higher rating?