adds gating stuff, writes all thresholds simultaneously, updates readme with example

db/daq_common.db

@@ -178,15 +178,14 @@ record(longout, "$(INSTR)$(NAME):STOP")
 record(ao,"$(INSTR)$(NAME):THRESHOLD")
 {
  field(DESC, "Minimum rate for counting to proceed")
- field(VAL, "0") # Rate
+ field(VAL, "1") # Default Rate
  # Could perhaps still be improved.
  # It seems to only accept whole counts?
  field(DRVL, "1") # Minimum Rate
  field(DRVH, "100000") # Maximum Rate
  field(OMSL, "supervisory")
  field(OROC, "0")
- field(OUT, "@$(PROTO) setMinRate($(INSTR)$(NAME):) $(ASYN_PORT)")
- field(DTYP, "stream")
+ field(OUT, "$(INSTR)$(NAME):THRESHOLD-F PP")
 }
 
 record(ai,"$(INSTR)$(NAME):THRESHOLD_RBV")