sending alarms to HMI

Hi,

Stuggling with alarms and the HMI, put the posting here as I think this is more a PLC question than HMI

I am struggling with understanding the data types needed for the HMI and passing and setting alarms

I am using a PLC1212C with a basic HMI KTP600

I have a "drill" and there is a timer, if the drill runs for longer than(x) an alarm is posted

I set a variable up in the PLC in a global data block as

ARRAY(0..7) OF WORD (drillalarms)

I have some code which moves '1" when the timer kicks in into Drillalarms[0]

I have then set up the HMI alarm (type acknoledgement needed)

The HMI alarm scans the Drillalarm[1] and I have sent the HMI acknowledge to Drillalarm[2]

This code works once, the alarm triggers and then I acknowledge it,. but unless I restart the HMI the alarm does not re-ucurre (or re-display)

Questions which hopefully will aid my understanding,

1. Is the data type in the PLC ok as it is, my intention was to use the data as follows

2. Does the plc tag need to have an acknowledge bit.Is my logic of assinging bit
0 of the tag to activate alarm and bit 1 as acknowledge

3 is setting these bits as 1 & 0 ok or does the HMI expect/insert other data

4 If the plc sends an alarm and the user acknowledges the alarm and the plc
enters another alarm state, does this create another alarm line in the HMI or
active the previous alarm. Ie, if I looked at acknowledged alarms, would there be
two entries or 1 ?

5 Is it correct that the HMI is writting to the PLC tag to confirm acknowledgment

6If I wanted to recreate a new occurance of the alarm after it had been confirmed,
I assume I change bit 0 to from 1 to zero, but would I also need to change the acknowledgment
bit back to 0, so the new alarm event is displayed.

Hope this makes sense, or that someone can point me in the right direction