Adressing

Just started working with the Siemens PLC 115U - CPU942B.

I have:
0: 16x 115/230V AC 1A (465-7LA 11)
1,2: 32x DC 24V 0,5A (441-7LA 12)
3: Analoge input: 16/8 channels (465-7LA 13)

This is a better view of the whole PLC/control:
http://stud.hro.nl/0762476/rek.JPG


My question:
I can't figur out, how I can let the PLC proces the Input (of a couple of Volts on the Analog Input) to an Output (of 0/1 on one of the Digital Outputs)? I know you have fixed addresses for the Analog Input (in this case: Slot 3 = 224-255), but how do I use them? Does anyone have a good example?

friendly greetings,

Timo

Hello timodc.

To get an analog input into the PLC, you can use the system function block FB250. You have to specify slot, channel number, the upper and lower limits of the scaled value, and where to store the scaled value.

edit:
You can also access the unscaled value via the in/out image (EWxxx). But you probably better scale the input to engineering values as the first thing.

To control a digital output from an analog input can be done in may ways.
One could be to test for below or above a limit value.

Can you give an code example?

thanks! and greetings,

TiMo

I dont have STEP5 installed, so I cannot open up old projects.
And I dont remember everything from memory.

Find the manual, and read up on FB250.

timodc - Is this related to the S5 to S7 project you have previously posted on ?

L D[AR2 said:

timodc - Is this related to the S5 to S7 project you have previously posted on ?

Click to expand...

no, this is just a hobby issue, working with this S5 PLC for fun.. but it isn't working out that easely..

Here is a link to a siemens manual that may assist.

http://support.automation.siemens.com/WW/skm/pdfviewer.asp?HitsPerSite=50&ehbid=html_76%2Fehb%2F1085937%2Ehtm&query=fb250&lang=en&nodeid=1118160&page=366&view=new

what is the DO you are requiring for yr systeam. Is it limit value monitoring or some thing else? Pl. eloborate

rthiyagu_00 said:

what is the DO you are requiring for yr systeam. Is it limit value monitoring or some thing else? Pl. eloborate

Click to expand...

It's more for practicing.. I'm now in my third year of the Higher Education Engineer here in the Netherlands.. that's the third of the four years... and I never got any information on PLC's.. or lessons.. or what so ever.. and now I'm trying to educate myself in the world of the PLC's.. so I don't really have specs of "my" machine.. it's just trying stuff out

in anyway.. thanks for all the information.. if anyone has anything else that can get me on my way.. please

greetings TiMo