fix autofill with extrnal level meter

when no value is available, filling must be inhibited.
this patch checks whether a value newer than 30 sec is
available

tcl/17tf.config

@@ -28,7 +28,7 @@ GraphAdd 17tf.nlevel      % N2_lev black
 #makeCCU4 blank nv
 #GraphAdd nv.flow      mbar nv_flow red
 
-makenv ln2fill -driver ccu4ext n2 "17tf nlevel"
+makenv ln2fill -driver ccu4ext n2 /17tf/nlevel
 
 
 #make17tfNv

tcl/drivers/ccu4ext.tcl

@@ -3,7 +3,7 @@ namespace eval ccu4ext {
 }
 
 # automatic fill with level reading from external source
-proc stdConfig::ccu4ext {type {readlevel 0}} {
+proc stdConfig::ccu4ext {type {readpath 0}} {
   
   variable node
   variable ctrl
@@ -27,13 +27,14 @@ proc stdConfig::ccu4ext {type {readlevel 0}} {
 
     node state upd -text
 
-    node readlevel -text par $readlevel
+    node readpath -text par $readpath
     prop visible false
     node lowlevel par 10
     node highlevel par 100
     
     node smooth upd
     prop fmt %.7g
+    prop geterror undefined
     default -1
 
     node minfillminutes par 3.0
@@ -89,7 +90,7 @@ proc ccu4ext::changestate {type state} {
 
 proc ccu4ext::calcsmooth {level minspeed maxspeed} {
   if {![string is double $level]} {
-    return 999.9
+    return 199
   }
   set now [clock seconds]
   set lasttime [silent 0 sct lasttime]
@@ -98,10 +99,7 @@ proc ccu4ext::calcsmooth {level minspeed maxspeed} {
   }
   set delta [expr $now - $lasttime]
   sct lasttime $now
-  set smooth [hvali [sct]/smooth]
-  if {$smooth < 0} {
-    set smooth $level
-  }
+  set smooth [silent $level hvali [sct]/smooth]
   set gs [expr $smooth + $delta * $maxspeed]
   if {$level > $gs} {
     set smooth $gs
@@ -126,6 +124,7 @@ proc ccu4ext::calcsmooth {level minspeed maxspeed} {
     }
   }
   hupdate [sct]/smooth $smooth
+  hdelprop [sct]/smooth geterror
   return $smooth
 }
 
@@ -148,7 +147,8 @@ proc ccu4ext::fillExt {type} {
     }
   }
   set errtxt ""
-  set sm [expr [DoubleTime] > [silent 0 sct change_time] + 10]
+  set now [DoubleTime]
+  set sm [expr $now > [silent 0 sct change_time] + 10]
   switch -- $valve {
     0 {
       set txt "fill valve off"
@@ -178,6 +178,12 @@ proc ccu4ext::fillExt {type} {
       set errtxt "unknown error"
     }
   }
+  set rdpath [hvali [sct]/readpath]
+  set level [hvali $rdpath]
+  set levelerror [silent "" hgetpropval $rdpath geterror]
+  if {$levelerror ne "" && $errtxt eq ""} {
+    set errtxt "$txt ($rdpath $levelerror)"
+  }
   if {$errtxt eq ""} {
     updateval [sct]/state $txt
     hupdate [sct]/status ""
@@ -189,11 +195,6 @@ proc ccu4ext::fillExt {type} {
     changestate $type fill
     return idle
   }
-  set level [silent invalid result [hvali [sct]/readlevel]]
-  if {! [string is double $level]} {
-    hsetprop [sct]/readlevel geterror "illegal $type level reading"
-    return idle
-  }
   set state [sctval [sct]]
   set now [clock seconds]
   set lowlevel [hvali [sct]/lowlevel]
@@ -219,6 +220,7 @@ proc ccu4ext::fillExt {type} {
       return idle
     }
     0 { # watching
+      validated_level
       set minspeed [expr - 100.0 / [hvali [sct]/minholdhours] / 3600.]
       set maxspeed [expr - 100.0 / [hvali [sct]/maxholdhours] / 3600.]
       set s [calcsmooth $level $minspeed $maxspeed]
@@ -231,13 +233,18 @@ proc ccu4ext::fillExt {type} {
         }
         # start fill
         hset [sct] 1
-        clientput "$type level low - start fill"
+        clientput "$type level low ($level smooth $s) - start fill"
       } else {
         changestate $type stop
       }
       return idle
     }
-    1 {
+    1 { # filling
+      if {[validated_level] eq ""} {
+        hset [sct] 2
+        changestate $type off
+        return idle
+      }
       set vcmd [silent 0 sct vessel_cmd]
       # check that vessel command works
       if {$vcmd ne "0" && [catch {[result $vcmd]}]} {
@@ -246,7 +253,7 @@ proc ccu4ext::fillExt {type} {
          set vmd 0
       }
       set now [clock seconds]
-      set s [hvali [sct]/smooth]
+      set s [silent $level hval [sct]/smooth]
       sct minlevel [silent 999 sct minlevel]
       if {$s < [sct minlevel]} {
         sct minlevel $s
@@ -321,12 +328,30 @@ proc ccu4ext::fillExt {type} {
   return idle
 }
 
+proc ccu4ext::validated_level {} {
+  set rdpath [hval [sct]/readpath]
+  if {[DoubleTime] < [silent 0 hgetpropval $rdpath read_time] + 30} {
+     return [hval $rdpath]
+  }
+  if {[silent "" hgetpropval $rdpath geterror] eq ""} {
+    clientlog "ERROR: no reading of $rdpath within 30 sec"
+  }
+  hsetprop $rdpath geterror not_available
+  return ""
+}
+
 proc ccu4ext::writeExt {type {activate 1}} {
   sct update [sct target]
-  hupdate [sct]/smooth [silent 0 result [hvali [sct]/readlevel]]
   switch -- [sct target] {
 # watching
     0 {
+      set level [validated_level]
+      if {$level eq ""} {
+        changestate $type off
+        sct update 2
+        return idle
+      }
+      hupdate [sct]/smooth $level
       catch {logsetup [sct]/vext clear}
       hupdate [sct]/status ""
       eval [silent "expr 0" sct slow_cmd]
@@ -350,6 +375,13 @@ proc ccu4ext::writeExt {type {activate 1}} {
     }
 # fill
     1 {
+      set level [validated_level]
+      if {$level eq ""} {
+        changestate $type off
+        sct update 2
+        return idle
+      }
+      hupdate [sct]/smooth $level
       hupdate [sct]/status ""
       set vcmd [silent 0 sct vessel_cmd]
       if {$vcmd ne "0"} {

tcl/startup/autofill.tcl

@@ -19,7 +19,7 @@ proc makeHeFill {levcmd} {
     if {$levcmd eq "ccu"} {
       makenv hefill he_ext_ccu ccu
     } elseif {$levcmd eq "ccu4ilm"} {
-      makenv hefill -driver ccu4ext he lev
+      makenv hefill -driver ccu4ext he /lev
       lappend fast_cmd {lev mode 1}
       lappend slow_cmd {lev mode 0}
     } else {
@@ -90,7 +90,7 @@ proc makeN2Fill {{option ccu} {code 0}} {
     GraphAdd n2.upper K_2 N2_Upper red
     GraphAdd n2.lower K_2 N2_Lower green
   } elseif {$option eq "ccu4ilm"} {
-    makenv ln2fill -driver ccu4ext n2 "lev n2"
+    makenv ln2fill -driver ccu4ext n2 /lev/n2
     GraphAdd lev.n2 % "N2_level" black
     if {! $c} {
       # switch silently to inactive