ganutenator
Lifetime Supporting Member
Working on a project where I need to make the inputs and outputs assignable via an hmi.
Any tips would be appreciated.
Any tips would be appreciated.
tips on making i/o dynamic
- Thread starter ganutenator
- Start date
OkiePC
Lifetime Supporting Member
It would help to know a little more about the process. How many I/O are involved? What type of operation is this? Discrete assembly machine? Continuous process heavy on analog?
In general, I would think that your control program would not have any real I/O but use internal registers for them.
Then in a separate file (two of them) you would assign the inputs to the internal registers (one of the first program calls), and as the last routine you would assign the output registers to the real world addresses.
This is a common practice, but for your dynamic application, you may used indirect address for the actual I/O, and have the indexes set up as variables from the HMI:
It could be complicated depending on how wide ranging the I/O count is and what type of controller. If you need to be able to assign an output to any point among slots 2,3,9, 12, or remote rack 7 slots 3 or 4, that could be hairy.
If the choice is limited to a single chassis slot, then it could be pretty simple.
In general, I would think that your control program would not have any real I/O but use internal registers for them.
Then in a separate file (two of them) you would assign the inputs to the internal registers (one of the first program calls), and as the last routine you would assign the output registers to the real world addresses.
This is a common practice, but for your dynamic application, you may used indirect address for the actual I/O, and have the indexes set up as variables from the HMI:
It could be complicated depending on how wide ranging the I/O count is and what type of controller. If you need to be able to assign an output to any point among slots 2,3,9, 12, or remote rack 7 slots 3 or 4, that could be hairy.
If the choice is limited to a single chassis slot, then it could be pretty simple.
ganutenator
Lifetime Supporting Member
OP
All discrete.
Don't know the final i/o count but so far under 32 inputs and 32 outputs.
ganutenator
Lifetime Supporting Member
OP
(*Using this routine to map the inputs to the
Input_Array for use w/ the functions*)
input_pointer:= 0;
While (input_pointer <= 63) Do
input_array[input_pointer]:= %M0[input_pointer];
input_pointer:= input_pointer + 1;
End_While;
Input_Array for use w/ the functions*)
input_pointer:= 0;
While (input_pointer <= 63) Do
input_array[input_pointer]:= %M0[input_pointer];
input_pointer:= input_pointer + 1;
End_While;
Last edited:
ganutenator
Lifetime Supporting Member
OP
Step 1: break it down to its pieces parts
Steve Bailey
Lifetime Supporting Member + Moderator
I've never done anything similar, but here's how I'd start.
I'm going to assume that the hardware configuration is fixed. By that I mean that the input modules will always be in the same locations.
Start with a Boolean array called "Inputs" with the module data mapped to it. Slot1, Point 1 mapped to Inputs(0), Slot 1, Point 2 to Inputs(1), Slot 2, Point 1 to Inputs(16), etc.
If your logic contains a variable named "Positive_EOT_Limit_Switch" that could be wired to any of the discrete inputs you will need an HMI screen where the user can assign elements of the "Inputs" array to the names of the discrete inputs and a line of code like:
Positive_EOT_Limit_Switch = Inputs(HMI_Index)
I'm going to assume that the hardware configuration is fixed. By that I mean that the input modules will always be in the same locations.
Start with a Boolean array called "Inputs" with the module data mapped to it. Slot1, Point 1 mapped to Inputs(0), Slot 1, Point 2 to Inputs(1), Slot 2, Point 1 to Inputs(16), etc.
If your logic contains a variable named "Positive_EOT_Limit_Switch" that could be wired to any of the discrete inputs you will need an HMI screen where the user can assign elements of the "Inputs" array to the names of the discrete inputs and a line of code like:
Positive_EOT_Limit_Switch = Inputs(HMI_Index)
bernie_carlton
Lifetime Supporting Member + Moderator
You might about how to prevent incompatible assignments. But it may not be as simple as detecting two input functions tied to the same point. It will depend on your process,
http://accautomation.ca/building-a-plc-program-that-you-can-be-proud-of-part-6/
The above is a post that was done by changing the sequence of valves based upon user input through a HMI. In this case the AdvancedHMI was used and communicated Modbus TCP to a Do-More PLC.
I thought that this may give you some ideas,
The above is a post that was done by changing the sequence of valves based upon user input through a HMI. In this case the AdvancedHMI was used and communicated Modbus TCP to a Do-More PLC.
I thought that this may give you some ideas,
It is impossible to reassign the real I/O however it is possible to do it in an array, example:
input[0]:= %IX0.0 etc.
in the program itself you can assign the array as you like.
assign[2]:=0
so the real is then state[2]:=input[assign[2]]
input[0]:= %IX0.0 etc.
in the program itself you can assign the array as you like.
assign[2]:=0
so the real is then state[2]:=input[assign[2]]
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