Cheapest path to adding some discrete IO to Siemens CPU317-2 DP for learning setup.

AutomationTechBrian

Lifetime Supporting Member
AutomationTechBrian
Join Date
Jul 2013
Location
St. Cloud, MN
Posts
669
I almost have a complete, basic setup for a shop/learning fixture. I've got a used CPU317-2 DP, a G120C, and some purple hose. I'd like to add some cheap, discrete IO, obviously on Profibus. Question for the Step 7 Classic guys: what would you recommend? It's my own money, and it's just for setting up a test lab, so I'm trying to be frugal. Thoughts?

I'm also hoping to stumble on a cheap MMC.

S7 CPU317-2 DP.png
 
No it doesn't. That's right... I hadn't thought of that. I just assumed a 3rd party IO would be a cheaper rough, though. I need to find a part number and check on Ebay.
 
There is a simulator module with digital switches built-in:

6ES7 374-2XH01-0AA0

For DC Inputs:
6ES7 321-1BH0x-0AA0 (replace 'x' with 0, 1 or 2)

For DC Outputs:
6ES7 322-1BH0x-0AA0 (replace 'x' with 0, 1 or 2)

Don't forget the front connector (if it's not included)!
6ES7 392-1AJ00-0AA0

Also make sure they supply the backplane connector.
 
Last edited:
I'm always so glad when I take the time to ask about things like this!

I picked a simulator module for $20. I should have it by Friday. I don't see any mention about the backplane connector, though. I asked a question about it. If there isn't one, do you know the part number?
 
...and a new, 512KB MMC for $50, coming from the next state over from me.

I was going to just grab a backplane connector because they are cheap, and there are plenty of them. But when you look, they are all coming from China, or Hong Kong, or Egypt, etc. That might end up taking some time. I'm still looking for an inexpensive one from the US.

MMC.png
 
Do you really need the I/O, for most simulations you could use internal memory bits, sometimes this is better as you can then build in routines that simulate the real I/O, obviously, for things like Start/Stop buttons then you have to force them, however, for I/O like valve feedback and so on then a simple bit of code in a sim block. This can be used for all sorts of simulation including analogues etc.
Here is a example of simulating a valve with position sensors:
I may have not got the actual reason for adding real I/O but it is worth thinking about.
The only caveat is the setup of the real I/O cannot be done.
If eventually you need real I/O for a project you create blocks of code that map the Real I/O into and out to internal memory, then on testing completion disable or remove the simulation blocks and enable the I/O mapping.

Sim.png
 
Last edited:
AutomationTechBrian said:
MMC card... I'm trying to figure out if there is a difference, other than the size. Are all Siemens MMC cards compatible?
Click to expand...


Fair warning, I think some of the older HMIs used an MMC as well, which wasn't compatible with the PLC MMC. Probably would have had an HMI part number though, so as long as you stick to 6ES7 stuff, as the other poster said, you should be fine.


Newer PLCs use SD cards instead of MMC. Looks the same, but the description should be changed. Also the newer ones are black instead of the ugly blue-green.
 

Similar Topics

A
What is the cheapest device-level ring supervisor...
..that you know of, other than the 1783-ETAP A? I am trying to setup a device-level ring testing setup environment for training that I may need...
Replies
2
Views
1,479
AlfredoQuintero
A
rjk_cmh
Absolute cheapest way to do simple logic on many points
I have an application that needs 20 inputs and 20 outputs with only 10 XNOR and 10 NAND blocks. I could do it with relays, but this could end up...
2
Replies
16
Views
5,156
rjk_cmh
rjk_cmh
E
Cheapest Codesys PLC
Hello, What would be the cheapest PLC running codesys I would be able to get my hands on? I like to expand my mind and I started out as an AB guy...
2 3
Replies
30
Views
13,423
ArcReactorKC
A
O
Current (2020) Cheapest AB learning systems
I want to fill a hole in my skillset by picking up AB PLC programming. Although I'm at a very advanced level with GE PLCs (I mean GE-IP, no I...
Replies
9
Views
3,329
drbitboy
drbitboy
P
Absolute cheapest Remote IO ?
What are some reliable but low cost options for an ethernetIP based remote IO you can get ? I need a few to communicate with a Rockwell...
2 3
Replies
38
Views
15,035
kwade
K
Back
Top Bottom