Two possibilities I know:
Use the alarmprogram, normally this is triggered. Check in this script for a severity of 5 (Panic, IDS crash). This is the first incoming parameter. Of course this only works if IDS still calls the alarmprogram. Most of the time this will work.
To monitor specific instances there is a dirty way to do yhe job. Create two symbolic links that point to the oninit process (for exampe oninit_inst1 and oninit_inst2). Now start instance 1 with oninit_inst1 (and instance 2 with ....).
Now you will see serveral ononit_inst1 processes en aseveral oninit_inst2 processes. With this you can monitor a specific engine.
Hope this helps,
Rob Prop