Unity, EBool, Latched coils

I have to convert a 984 PLC to Unity and have the following problem.


1. In Modsoft are 2 types of coils, normal and latched. Normal coils go zero at startup of the PLC, no matter of their values before shutdown.
Latched coils keep their last value before shutdown.
I do not see a latched coil in Unity. How do I make normal and latched coils in Unity?


2. What is the difference between Bool and EBool variables and how to use them in Unity? Are they interchangeable? When is it allowed to use each of the types. And more important, When is it Not allowed to use each type?

Regards,
Robert

Equivalent of latch /unlatch in unity is set/reset. I do not know the difference between bool and ebool. I always use ebool. Are you using FBD or LADDER? In ladder it's S and R, in FBD it's SET and RESET. You find these under EDIT-->FFB INput ASSISTANCE.

I use BOOL when I need to access bits of the word. I declare a variable with address, for example, %MW10.3, and it's type is BOOL. The difference of EBOOL is that it also contains information about edges.

I think you can try to use unlocated variables as "Normal" coils, and located ones - as "Latched".

Thank you for answering.

Located variables are also used for communicating with IO and HMI via Modbus.
Most of this variables have to be zero after shutdown and restart.
Maybe there are more solutions for this issue?

If I did understand you right, so EBool is like Bool but with extra information and features (edge dedection) that dont have to be used. So EBool can be used as Bool but Bool cant always be used as EBool.
Please write me if I have understand right.

Regards,
Robert

You can copy BOOL to EBOOL and EBOOL to BOOL, they are compatible. But you can't use BOOL as an effective parameter in FBs (EFBs, DFBs) when the formal one is EBOOL.

EBOOL Variables are:
- internal bits (%M)
- inputs (%I)
- outputs (%Q)
BOOL variables are:
- system bits (%S)
- word extracted bits (%MWx.y)
- module error bits
- channel error bits
etc.

You can initialize any located variables on the first scan (ST example):
IF %S1=1 (*WARM RESTART*)
THEN
Coil_1 := 0;
Coil_2 := 0;
END;

Robert
Your definition of Bool and Ebool is correct. Just for interest a variable declared as either type will use a byte of memory, except if the variable is a located bit in a word. In this case it must be a Bool and it only uses the single bit.
To retain (or clear) the state of any variable there are properties for each variable to determine how they behave (right click and select properties then look at the properties window)

Thank you for your help.
The last two answers makes all clear.

I am using EBOOL for passing input/output variables to a CUSTOM
DFB, but I get an error saying that they need to be unlocated EBOOL's. This seems like a major issue to me, that you cant modify the contents of an EBOOL in a DFB. Am I doing something wrong here?

The error I get is:

(E1225 DFB cannot access EBOOL variable mapped to State Ram on Quantum target, unlocated EBOOL required)


I am using Unity 3.0 on a Quantum 434 12U

Thanks!

**Update**

I dont seem to get the error, if I declare seperate input and output variables instead of using the input/output variable. I wonder why.

Found the difference

Pfa