throughput of Siemens 319F PLC

[Mechamania]

Hi

Can anybody tell me what the throughput of the Siemens 319F PLC is?
Thus the time from reading the sensor data, processing the data and the output to for instance a brake system.
Is that time programmable? What is the minimum (fastest)?

I hope someone can help me find this information.

 

[Mike_RH]

You are not providing enough information.
What are your field input devices? What are your field output devices?
What field bus are you using (DP/PN)?
What programming will be required to accomplish your safety logic?

What response time do you need?

Check on the Siemens support site, Siemens has an Excel spreadsheet to help you gather the information you need and calculate the response time for various CPU's.

Here is the link: http://support.automation.siemens.com/WW/view/en/25412441

 

[OzRoo]

You really need to look into your project in more detail, there are a couple different versions of the 319F, if I remember right it was around $7k for just the PLC itself, it might be overkill for what you want, a 313F may do the job, personally I'm not a Siemens fan, (Not an AB Fan either) but if they are what you are used to then go for it. The questions you are asking are not of the detail of a project big enough to need a 319F. I suspect if your project is that big you need a lot of profesional specialised engineering input on that end. I'm just a sparky but have been deeply involved in both of the projects I mentioned in the other thread, but we left the spec of that hardware to the programmers to what they needed.

If you are just controlling one motor brake you may find a $200 Delta PLC will do the same job. And use a separate Pilz Programable Safety Controller which is like a dumbed down PLC for the safety.

 

[Mechamania]

Thanks Mike for the link to the excel sheet. Looks quite complex. I do not yet understand how to use it. I will have to study it further. But the response time numbers on the last sheet do scare me.

At OzRoo: I'm not stuck to Siemens. But I was thinking it is one of the fastest. I would like a response (throughput) time of 10 mS. I start to think that that is not possible.
I will need about 20 (analog) inputs and I have to do some calculations too. Depending on the sensor inputs, machine limits are calculated. If something is wrong the machine should be stopped. Preferrabe within 10 mS from reading the sensor values.

 

[OzRoo]

Yeah, 10ms is damn quick, pretty flat out getting contactors to open at that speed and the momentum of product to stop
Do you actually need it to stop or just be stopping, is it a safety requirement or due to the nature of the product accuracy / wastage?

We can't stop our beam press that fast but calculations on the 500mm gap between the light curtains and press blade mean it should be stopped before a person can touch the tooling.

The other option is in other safety zones we have solenoid gate locks with a button next to them, if an operator wants to get in they press the button, the machine stops when it's ready, then unlocks the gate. The only way to immediately unlock the gates is an E-Stop.

 

[JesperMP]

I will need about 20 (analog) inputs and I have to do some calculations too. Depending on the sensor inputs, machine limits are calculated. If something is wrong the machine should be stopped. Preferrabe within 10 mS from reading the sensor values.

That will be doable.
You may have to consider fast analog inputs such as 6ES7331-7HF01-0AB0.
If the calculations arent extremely complicated you can use a 317 or even a 315.

 

[Mechamania]

Yeah, 10ms is damn quick, pretty flat out getting contactors to open at that speed and the momentum of product to stop
Do you actually need it to stop or just be stopping, is it a safety requirement or due to the nature of the product accuracy / wastage?

I want the machine to start the stopping within 10 mS.

 

[Mechamania]

That will be doable.
You may have to consider fast analog inputs such as 6ES7331-7HF01-0AB0.
If the calculations arent extremely complicated you can use a 317 or even a 315.

That is good to hear!
Does this also apply for the Safety versions?
315F, 317F?

Somebody told me the Safety versions are 10 times slower!!??

 

[TurpoUrpo]

You need to consider the impact of safety program execution. It is executed by interrupts. Its not "slower" but it has impact.

 

[Bratt]

If you want the best performance look at a pc based controller
It is also avaible in a fail safe version an in a S7-300 format

 

[boneless]

are you set on a safety PLC? you will easily be able to get the time you need if you don't, and save some major money as well..

 

[JesperMP]

Unless the calculations mentioned are very complex, or there are some other processorburdening tasks, then I think that there is no need for a superpowerful CPU.

Even if there are some other tasks eating away at the CPUs scan time, you can use a cyclic interrupt to take care of the timecritical stuff.