Array of Digital Alarms

"Digital_Alarms" FB2 input "Number_of_Alarm" needs a value of 1 for the FB to know how many alarm inputs are present.

If it "just happens" to work with 0 (default value) assigned to "Number_of_Alarm", that means there is a bug in the original code from the referenced site, or you made a mistake manually copying their example into your project, or both.

For FB2 to work, you do not need to know anything about state machines.

Also, in the referenced URL, they missed one factor that I find curious.  For the state machine they were implementing and passing various states and status signals that implied an alarm condition existed, they used hard-coded state machine values, like 0,1,2,...

What they should have done (IMHO):

PLC Tag Table -> User Constants

User Constant Name        Value

System_Startup_State_0      0
System_Init_Starting_1      1
System_Init_Completed_2     2
System_Control_Power_Off_3  3
System_Control_Power_On_4   4
...

Then when they compare the "state_machine_db".state, they are not comparing against some integer and no context, they are comparing with a tag with context that happens to have a value assigned.

I know that user-constant tip has no meaning on your Array of digital alarms, but it may help you understand the dig alarm URL's content where it referenced (and provided URL to other) state machine information for further study.

milos23

Hi,

Frome here I stole an idea of how to use an array of digital alarms:

https://www.solisplc.com/tutorials/alarms-and-diagnostics-in-siemens-tia-portal

I couldn't digest all it all, because I haven't dealt with state machines untile now, and I really don't need them anyways.

What I got at the end of an experiment is in attached pdf (it is very simple), and it is somehow working, but I am not sure is it reccomendable/ligal way to manage alarms. 

How does it works anyways, Alarm_Inupt_0 - 15 input tags are NO bools, but when I close %M51.1, which is connected to Alarm_Input_0 in "Main" block - alarm is activated?