event_log: add EventTable NTTable.

Instead of requiring clients to combine multiple waveforms themselves,
provide a table with timestamp and event information. Since the tablej
uses a double value as the whole timestamp, it only supports up to
microsecond accuracy.

It was necessary to add a top level trigger mapping to rstSoftBuff,
otherwise, when resetting the buffers, the table would have one element
from each buffer, due to their spurious processing; so we needed to
fetch the values again after the buffer reset was completed.

timingApp/Db/event_log.db

@@ -205,6 +205,19 @@ record(compress, "$(P)$(R)SUBSECbuffer"){
   field(FLNK, "$(P)$(R)TSbuffer")
 }
 
+record(aai, "$(P)$(R)bufferLABELS"){
+  field(ASG, "Reserved")
+  field(NELM, 2)
+  field(FTVL, "STRING")
+  field(INP, {const:["Timestamp", "Event"]})
+  info(Q:group, {
+    "$(P)$(R)EventTable-Mon": {
+      +id: "epics:nt/NTTable:1.0",
+      "labels": {+type: "plain", +channel: "VAL"}
+    }
+  })
+}
+
 record(compress, "$(P)$(R)TSbuffer"){
   field(ASG, "Reserved")
   field(DESC, "TS circular buffer")
@@ -213,6 +226,11 @@ record(compress, "$(P)$(R)TSbuffer"){
   field(NSAM, "1000")
   field(INP, "$(P)$(R)LOGTS")
   field(FLNK, "$(P)$(R)EVENTbuffer")
+  info(Q:group, {
+    "$(P)$(R)EventTable-Mon": {
+      "value.A": {+type: "plain", +channel: "VAL"}
+    }
+  })
   field(PREC, 6)
 }
 
@@ -223,6 +241,11 @@ record(compress, "$(P)$(R)EVENTbuffer"){
   field(NSAM, "1000")
   field(INP, "$(P)$(R)LOGEVENT")
   field(FLNK, "$(P)$(R)LOGSOFTCNT")
+  info(Q:group, {
+    "$(P)$(R)EventTable-Mon": {
+      "value.B": {+type: "plain", +channel: "VAL", +trigger: "*"}
+    }
+  })
 }
 
 record(calc, "$(P)$(R)LOGSOFTCNT"){
@@ -307,6 +330,11 @@ record(seq, "$(P)$(R)rstSoftBuffSeq"){
   field(LNK7, "$(P)$(R)SUBSECbuffer.RES")
   field(LNK8, "$(P)$(R)TSbuffer.RES")
   field(LNK9, "$(P)$(R)EVENTbuffer.RES")
+  info(Q:group, {
+    "$(P)$(R)EventTable-Mon": {
+      "": {+type: "meta", +channel: "VAL", +trigger: "*"}
+    }
+  })
 }
 
 record(longout, "$(P)$(R)cmd_log_get"){