alarms page

Hi guys

Im a beginner at PLCs and Im currently designing an alarm page and Im having trouble designing the alarms active rung do the OK alarms need to be in the alarms active rung Im designing an alarm page for a water tank with these alarms :

HI HI alarm
EstopOK alarm
heater MCB OK
pumps MCBs OK
Valves Inlet and Outlet MCB OK
Agitator MCB OK

so in the alarm active rung do I just put the HI HI alarm in, or do I put all the others in aswell, and if i do how If I put the ok alarms in the rungs NO contacts they will close they are always on,

Please help it is my first time doing an alarm page



cheers

nick

Nick85 said:

Hi guys

Im a beginner at PLCs and Im currently designing an alarm page and Im having trouble designing the alarms active rung do the OK alarms need to be in the alarms active rung Im designing an alarm page for a water tank with these alarms :

HI HI alarm
EstopOK alarm
heater MCB OK
pumps MCBs OK
Valves Inlet and Outlet MCB OK
Agitator MCB OK

so in the alarm active rung do I just put the HI HI alarm in, or do I put all the others in aswell, and if i do how If I put the ok alarms in the rungs NO contacts they will close they are always on,

Please help it is my first time doing an alarm page



cheers

nick

Click to expand...

i think you need to be a bit more specific in your question, alco think about rephrasing it as it does not make much sense at the moment

what do you mean "screen" are you trying to get a alarms showing on am HMI or SCADA system ?

what have you written so far and what are the specific problems you are having ?

Normally for triggering\logging alarms you just need to trap the error and set a coil in the PLC for each alarm you require, and let the graphics or HMI page look after the rest

what I mean is, Im designing a alarm page for a water tank, in the alarm page is all my alarms I have mentioned above at the bottom of the alarm page is supposed to be an ALarms/active rung If the Alarm/Active output is true the process will not run only when starting the process up if the process is already running and the Alarm/active output is true it will not stop the process,

the alarm/active rung is supposed to contain all the alarms, so if an alarm becomes true then the alarm/active output becomes true.

Im having trouble designing the Alarm/active rung, because all the OK alarms are always true if they are ok, and if the output of those alarms are true (because they are supposed to be ) then they will turn the alarm/active output true and you won´t be able to start the process
Estop................Estopok
----l/l-------------------()
Estok....faultReset.l
-l l-----l/l-----------l

Estopok...Alarm/active
--l l--------()
HI HI AL.l
--l l------l

If you still dont understand ill send u some more information

thanks nick

Your way of phrasing a question is very confusing and your terminoogy is also a little odd, what has the page go to do with it ?

What you want to do is monitor faults and stop the process working for several faults, or alarms as you acall them, is that correct ?

tragically1969 said:

Your way of phrasing a question is very confusing and your terminoogy is also a little odd, what has the page go to do with it ?

What you want to do is monitor faults and stop the process working for several faults, or alarms as you acall them, is that correct ?

Click to expand...

The way I see it it will be a Status Page for the Tank or whatever that will also include alarms. Kind of a one-page includes all deal for that tank.

Hello Nick,

I am not absolutely sure what it is you are asking for.

Have a look at this (over-simplified) bit of ladder and let me know if it's something like this you are after?

Rich.

You don't really need both rungs 0000 and 0001, just one of them will suffice, then use either a XIC (-||-) of ALL_OK in rung 0002 (as shown) OR use a XIO (-|/|-) of FAULT_ACTIVE in 0002

You would also need to consider whether or not you wish to 'LATCH' the alarms, and the logic necessary for enabling a RESET for them.

Let me know if I am on the right track for you?

Rich.

I often design alarma to be failsafe, ie the loop are closed in normal condition and opens when alarm. This way I monitor the whole loop, a wirebreak also gives alarm. It cost no more and includes no more hardware.