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Author Topic: Newbee cannot locate the tie between the real I/O and labels  (Read 7563 times)

PLCgadgets

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Newbee cannot locate the tie between the real I/O and labels
« on: March 27, 2009, 02:19:47 PM »
Hello, I am new to this ladder type of programming PLCs.  I have the DL205 with a variety of modules.  I don't understand how the "real world" relays in my I/O module is addressed?

Where is the assignment made and how do you determine which I/O pin of each module is labled?

I have an 8 input I/O how do I know which lable I should use?  Like X0 = first active I/O in the module?  Or better yet I have 8 N.O. relays in one of my modules.  How do I point to each relay location?

I realize this must be a basic concept but I cannot find this information in the manuals.

Thanks,

Gadget

b_carlton

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Re: Newbee cannot locate the tie between the real I/O and labels
« Reply #1 on: March 27, 2009, 02:28:03 PM »
If you are online with your PLC then under 'PLC' in the menu select 'Configure I/O'. This should provide a list of your modules and the starting address of any inputs (X) or outputs (Y) in each module. Remember that the addressing is in octal.After address X7 would be address X10.

If offline then look up the documentation for each module noting the used inputs and outputs. The first input in your rack after the CPU will be at X0. (Note: some mosules use NO I/O - like the CTRIO module). Some have both inputs and outputs. Some don't have an even multiple of 8 items. Any module, if it uses any of a type (either inputs or outputs) allocates space in 8 unit chunks. Thus if a hypothetical module only had 4 inputs and started at X0 then it would actually map its inputs to X0 through X3 but X4 through X7 would not be usable as inputs and the next input module would start at X10.
An output is a PLC's way of getting its inputs to change.