Crimson 3.0 - Issue Writing Program

Hello everyone!

I am trying to write a program in Crimson 3.0 that will turn on an output if a number of tags are not equal to zero. When I hit the translate button a message box pops up and says "The left-handed side of operator '=' must be writable.

Here is my code:

// If any alarms are present on any of the controllers, sound the audible alarm via Output 1

if ( PLC1.Alarms != 0 ) {
[Module1.Variables.OutputCoil1] = 1;
}
else if ( PLC2.Alarms != 0 ) {
[Module1.Variables.OutputCoil1] = 1;
}
else if ( PLC3.Alarms !=0 ) {
[Module1.Variables.OutputCoil1] = 1;
}
else {
[Module1.Variables.OutputCoil1] = 0;
}

end

Is it possible to turn on an output with a program or not?

Is "Module1.Variables.OutputCoil1" a tag? If so it must be set up as writable in the tag properties, and you shouldn't have square brackets around it. (Square brackets are used when directly addressing a register in an external device without a tag.)

Here's a shorter way to accomplish the same thing:
Module1.Variables.OutputCoil1 := (PLC1.Alarms!=0 || PLC2.Alarms!=0 || PLC3.Alarms!=0)

Your program will also have to run repeatedly to work correctly, like in the On Tick action.

I have gotten into the habit of always using two characters when performing any operation involving the equals sign

"==" test for equality
":=" assignment, which is how an equal sign all by itself gets translated.

With that said, John is right, your tags need to be set as read/write on their properties. You can fix one of them, and then copy and paste that property by selecting all the others and then pasting special > selective > pick the property you want to paste from the list.

I have it set up to run on Tick action. I am trying to write directly to the output of the module. Can that be done or not?

It looks like I need to write to Output1 and not OutputCoil1. OutputCoil1 is read only

You can also simplify things a lot:

[Module1.Variables.Output1] = (PLC1.Alarms || PLC2.Alarms || PLC3.Alarms);

The || operators treats each of arguments as a logical value, which for a numeric means whether it's equal to zero. It returns true (or 1) if either argument is true. So the code above will set the output to on if any of those values is not equal to zero, and to zero otherwise.

MikeGranby

Click to expand...

Hey Mike! glad to see your around still around...