Siemens S7-1500 Home Project

Hi All and a Happy New Year,
I have been a long time reader but this is my first topic. Early last year after having previously passed my Controllogix Certificate Program with Rockwell at my own cost I decided to make my own Rockwell simulator box to keep my hand in on everything I learnt on the courses (see pic below).

https://flic.kr/p/QM8Gb9

Due to the cost of these courses I am creating a Siemens version of my simulator box as the other half thinks this would be cheaper than the Siemens courses to learn on with all the available documentation that can be found online.

I am just wondering if anyone out there in the know would be able to look at my wiring diagram as well as the official wiring diagrams all posted below to tell me if I have done anything incorrectly as the official wiring diagrams display the power out to each sensor coming from the pins in the input modules and the same for the commons on the outputs returning to the modules whereas I would like my projects sensors to be powered outwith the modules and vice versa on the common wiring to save on wiring. Hope this makes sense! thanks

https://flic.kr/p/QMcufs

DI16x24VDC

https://flic.kr/p/QMbNDd

DO16x24VDC

https://flic.kr/p/QQCDLT

AI8x10VDC

https://flic.kr/p/QBzc7S

AO8x10VDC

https://flic.kr/p/QBzaLf

thanks for your time!

cheers Callum

I think you got it wrong, if you want voltage inputs, you should definetly watch that the max voltage is 10V, not 24V, and I think you should brick 4,8,12,16 with Mana.

And I don't understand the "powering of sensor" when you made AI with potentiometers, and gave the example of AI with voltage inputs...

I think you should try to play with it a little before building the whole thing.
Also, why not to have both voltage and current inputs? Outputs also..

m_turk said:

I think you got it wrong, if you want voltage inputs, you should definetly watch that the max voltage is 10V, not 24V, and I think you should brick 4,8,12,16 with Mana.

And I don't understand the "powering of sensor" when you made AI with potentiometers, and gave the example of AI with voltage inputs...

I think you should try to play with it a little before building the whole thing.
Also, why not to have both voltage and current inputs? Outputs also..

Click to expand...

Hi there and thanks for your reply,
My understanding from the documentation is that the pins are powered by 24VDC as seen in Appendices 3 and 5 respectively at the bottom of each of the analog wiring diagrams and that appendices 1 and 3 are analog to digital convertors and Digital to analog convertors. Would these not reduce the voltage to the required 10 volts or am l missing the point?

Ah I see where I messed that up. I was hoping to actually use the 12V PSU to power the pots as it can be reduced down to 10V but this doesn't seem like it can be done as there is nowhere on the module where I can put my commons. I think I will have to power the pots through pins 3, 7, 11 etc, that is what I meant with my powering of sensors comment. What do you think?

Would daisy chaining pins 3 to 4, 7 to 8, 11 to 12, 15 to 16 on the front connector work in implenting Mana?

Thanks once again Callum

AI CH0 (Voltage)
1 = +24VDC OUT (sensor supply)
3 = 0-10V in
4 = 0VDC

I would make voltage divider with pot and normal resistor and taking +24VDC from 1st terminal/Channel

Resistor 1,4kOhm and pot 1kOhm makes 0-10V and if you like use 4-20mA, then choose 1200ohm resistor and 5000 ohm pot

https://www.google.fi/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwi9kui9r6TRAhXCBSwKHZQiDIoQFgghMAA&url=https%3A%2F%2Fcache.industry.siemens.com%2Fdl%2Ffiles%2F205%2F59193205%2Fatt_112065%2Fv1%2Fs71500_ai_8xu_i_rtd_tc_st_manual_en-US_en-US.pdf&usg=AFQjCNHiqTua7KFaMNVEP9TgzkvoVd9Brw

mangy1983 said:

Would daisy chaining pins 3 to 4, 7 to 8, 11 to 12, 15 to 16 on the front connector work in implenting Mana?

Click to expand...

Nope, 4,8,12,16 to Mana.

Lare said:

AI CH0 (Voltage)
1 = +24VDC OUT (sensor supply)
3 = 0-10V in
4 = 0VDC

Click to expand...

This.


If you watch the manual on every way of connecting, you can get what every pin is exactly... Every module is different... But usually - 24V, Iin, Uin, 0V. Or something like that.. And don't forget to set the input setting in hardware configuration right...

Hi All and thanks to everyone who has replied to the topic so far,
I have to confess that I had no idea what Mana was until I googled it which incidentally brought me back to this forum topic here.

I am focusing solely at the moment on the AI module wiring as that seems to be the area that needs most attention. Is it possible at all to use an external PSU with 10VDC outwith the power out pins on the module like this as this is similar to how I wired up my Allen Bradley AI module bar the 24VDC connections??

[/url]https://flic.kr/p/QDo4Bb

Failing this I will be taking Lare's advice on reducing the 24VDC with a 1.4k Ohm Resistor

thanks once again Callum

Hi, I would go for current inputs, this way you don't need an external 10V supply.

Get a 5k (ish) pot meter and a 1k resistor, works pretty good for me!

boneless said:

Hi, I would go for current inputs, this way you don't need an external 10V supply.

Get a 5k (ish) pot meter and a 1k resistor, works pretty good for me!

Click to expand...

Hi boneless,
Unfortunatedly I have now bought all the gear bar the cpu. Im more into the programming aspect of PLC's / SCADA but I am slowly learning (sometimes the hard way) about the kit itself which is another reason for these projects.

I am hoping to make an extension box of inputs / outputs for the Siemens / AB projects next year so I was hoping to keep the wiring of the Siemens project as similar as possible to the completed AB project so that one extension box would fit both.

I was going to use dupont terminals to fit the terminals to their corresponding pins on each company's modules which is why I am tied down the way I am on this current project. I am going to incorporate current inputs / outputs for this box but need this project completed first. Do you think that my last wiring diagram is doable?

thanks Callum

mangy1983 said:

Do you think that my last wiring diagram is doable?

Click to expand...

should work if you connect to pins 3 and 4

Lare said:

should work if you connect to pins 3 and 4

Click to expand...

Hi Lare!,
You just made my day with that as I had already bought a 12VDC PSU that can be reduced down to 10VDC already for this purpose.

thanks once again.

Cheers Callum

Thinked again after sleeping.

You propably need to connect it this way. AI channel's internal resistance is big when voltage is selected, so connecting pot and voltage source series won't give full 0-10V scale.

This updated schematic don't differ from +24V and 1,4kohm resistor connection more than now you have 10V directly to pot and with 1,4k resistor you make 14V to heat before pot.

Lare said:

Thinked again after sleeping.

You propably need to connect it this way. AI channel's internal resistance is big when voltage is selected, so connecting pot and voltage source series won't give full 0-10V scale.

This updated schematic don't differ from +24V and 1,4kohm resistor connection more than now you have 10V directly to pot and with 1,4k resistor you make 14V to heat before pot.

Click to expand...

Hi Lare,
Apologies. This was how I was going to physically wire up the potentiometers. I just wasn't sure how to show it in a wiring diagram. Would it be ok do you think to daisy chain all of the Mana's on the module together with a single wire going back to the source PSU to save on cabling?

thanks once again Callum

Potentiometers have same power supply, so you can connect 0vdc pins to together. Fuse 1A is more than enought.

On real industry environment it isn't allways recommented, different channel share same 0vdc then, and channels aren't galvanically isolated anymore of each other. It can lead to ground loops.
Especially if different instruments are fed from different power sources and cablings are long. (Grounds and 0VDCs are not in same level)

But some AI-cards even share 0Vdc pin to several different channels from the box and others have own 0Vdc pin for every channel. So it depends.

Lare said:

Potentiometers have same power supply, so you can connect 0vdc pins to together. Fuse 1A is more than enought.

On real industry environment it isn't allways recommented, different channel share same 0vdc then, and channels aren't galvanically isolated anymore of each other. It can lead to ground loops.
Especially if different instruments are fed from different power sources and cablings are long. (Grounds and 0VDCs are not in same level)

But some AI-cards even share 0Vdc pin to several different channels from the box and others have own 0Vdc pin for every channel. So it depends.

Click to expand...

Hi Lare,
Thanks for the diagram. I am clear now on how to continue with wiring my project. I do wonder though if I need to connect a 24VDC connection at all to the input modules pins as I will be using an external 10VDC PSU to power the sensors as per the diagrams.

thanks once again cheers Callum

+24VDC is used to inner circuit to measuring channels. So yes you need two connections of power.
One for card itself and other for sensors for making voltage or mA data to channels.

It can be used from same supply (+24VDC, or separate DC or AC source ).
depending how measuremt is connected and how it takes power, there is 2, 3 or 4wire connection and talk of passive and active power conecction to PLC.

Analog output card makes usually voltage or mA of card supply.

Digital outputs are relay or transistor outputs. Relay card needs separate power, transistor outputs give voltage out directly.