diff --git a/site_ansto/instrument/config/environment/hiden_xcs.sct b/site_ansto/instrument/config/environment/hiden_xcs.sct
index 6a6e9f2d..88574944 100644
--- a/site_ansto/instrument/config/environment/hiden_xcs.sct
+++ b/site_ansto/instrument/config/environment/hiden_xcs.sct
@@ -1,8 +1,9 @@
 #
 # Simple driver generator for the Hiden Isochema XCS vapour delivery system
-# vim: ts=8 sts=2 sw=2 expandtab autoindent smartindent
+# vim: ts=8 sts=2 sw=2 expandtab autoindent smartindent nocindent
 #
 driver hiden_xcs_gen = {
+  # driver_property douglas = clowes
   usecreatenode = false
   vendor = hiden; device = xcs; protocol = std;
   class = environment
@@ -14,17 +15,20 @@ driver hiden_xcs_gen = {
 # Unnamed group has variables at device level
 #
   group = {
+    # group_property douglas = clowes
     type = float
     priv = user
     var temperature
     var flow1
     var flow2
     var flow3
+    var gas_factor = { value = 1.0; }
     var humidity = {
       driveable = humidity
       readable = 1
       read_command = '?ALL DATA'
       read_function = read_all_data
+      checkrange_function = chkrange_function
       value = 50
       lowerlimit = 10
       upperlimit = 90
@@ -35,22 +39,24 @@ driver hiden_xcs_gen = {
 # The named group is at the device level, variables below that
 #
   group analog = {
+    # group_property 'data' = true
     type = float;
     priv = user;
     readable = 1;
     read_function = read_sixteen;
-    var ain0 = { read_command = '?AIN,0'; };
-    var ain1 = { read_command = '?AIN,1'; };
-    var ain2 = { read_command = '?AIN,2'; };
-    var ain8 = { read_command = '?AIN,8'; };
-    var ain9 = { read_command = '?AIN,9'; };
-    var ain12 = { read_command = '?AIN,12'; };
+    property base = 0; # applies to all following vars
+    var pv1 = { read_command = '?AIN,0'; property span = 500; }; # ain0
+    var pv2 = { read_command = '?AIN,1'; property span = 500; }; # ain1
+    var pv3 = { read_command = '?AIN,2'; property span = 500; }; # ain2
+    var rhtemp = { read_command = '?AIN,8'; property span = 100; }; # ain8
+    var rhsense = { read_command = '?AIN,9'; property span = 100; }; # ain9
+    var ansto_temp = { read_command = '?AIN,12'; property span = 100; }; # ain12
     writeable = 1;
     read_function = read_twelve;
     write_function = write_twelve;
-    var aout0 = { read_command = '?AOUT,0'; write_command = '!AOUT,0,'; }
-    var aout1 = { read_command = '?AOUT,1'; write_command = '!AOUT,1,'; }
-    var aout2 = { read_command = '?AOUT,2'; write_command = '!AOUT,2,'; }
+    var sp1 = { read_command = '?AOUT,0'; write_command = '!AOUT,0,'; property span = 500; } # aout0
+    var sp2 = { read_command = '?AOUT,1'; write_command = '!AOUT,1,'; property span = 500; } # aout1
+    var sp3 = { read_command = '?AOUT,2'; write_command = '!AOUT,2,'; property span = 500; } # aout2
   };
   group digital = {
     type = int;
@@ -59,7 +65,13 @@ driver hiden_xcs_gen = {
     writeable = 1;
     read_function = read_digital;
     write_Function = write_digital;
-    var dout2 = { read_command = '?DOUT,2'; write_command = '!DOUT,2,'; allowed = '0,1'; readable = 5}
+    var dout2 = {
+      read_command = '?DOUT,2';
+      write_command = '!DOUT,2,';
+      allowed = '0,1';
+      readable = 5;
+      # property junk = junk;
+    }
   }
 
 #
@@ -82,7 +94,17 @@ driver hiden_xcs_gen = {
 @  if { [string equal -nocase -length 5 "${data}" "AOUT ="] } {
 @    set result [scan "${data}" "AOUT = %d OK" val]
 @    if  { ${result} == 1 } {
-@      set data [expr (100.0 * ${val}) / 4095.0]
+@      if { [hpropexists [sct] base] } {
+@        set base [sct base]
+@      } else {
+@        set base 0.0
+@      }
+@      if { [hpropexists [sct] span] } {
+@        set span [sct span]
+@      } else {
+@        set span 500.0
+@      }
+@      set data [expr (${span} * (${val} - ${base})) / 4095.0]
 @    } else {
 @      sct geterror "Syntax (Result=${result}) error in: '${data}'"
 @    }
@@ -94,7 +116,17 @@ driver hiden_xcs_gen = {
 @  if { [string equal -nocase -length 5 "${data}" "AIN ="] } {
 @    set result [scan "${data}" "AIN = %d OK" val]
 @    if  { ${result} == 1 } {
-@      set data [expr (100.0 * ${val}) / 65535.0]
+@      if { [hpropexists [sct] base] } {
+@        set base [sct base]
+@      } else {
+@        set base 0.0
+@      }
+@      if { [hpropexists [sct] span] } {
+@        set span [sct span]
+@      } else {
+@        set span 500.0
+@      }
+@      set data [expr (${span} * (${val} - ${base})) / 65535.0]
 @    } else {
 @      sct geterror "Syntax error (Result=${result}) in: '${data}'"
 @    }
@@ -104,13 +136,13 @@ driver hiden_xcs_gen = {
   }
   code read_function read_all_data = {
 @  if { [string equal -nocase -length 2 "${data}" "A "] } {
-@    set lust [split [string range "${data}" 2 end-3] ',']
-@    if  { [llength ${lust}] == 8 } {
-@      set data [expr [lindex ${lust} 0]]
-@      hupdate ${tc_root}/temperature [expr [lindex ${lust} 1]]
-@      hupdate ${tc_root}/flow1 [expr [lindex ${lust} 3]]
-@      hupdate ${tc_root}/flow2 [expr [lindex ${lust} 4]]
-@      hupdate ${tc_root}/flow3 [expr [lindex ${lust} 5]]
+@    set data_list [split [string range "${data}" 2 end-3] ',']
+@    if  { [llength ${data_list}] == 8 } {
+@      set data [expr [lindex ${data_list} 0]]
+@      hupdate ${tc_root}/temperature [expr [lindex ${data_list} 1]]
+@      hupdate ${tc_root}/flow1 [expr [lindex ${data_list} 3] / [hval ${tc_root}/gas_factor]]
+@      hupdate ${tc_root}/flow2 [expr [lindex ${data_list} 4] / [hval ${tc_root}/gas_factor]]
+@      hupdate ${tc_root}/flow3 [expr [lindex ${data_list} 5] / [hval ${tc_root}/gas_factor]]
 @    } else {
 @      sct geterror "Syntax error (Result=${result}) in: '${data}'"
 @    }
@@ -121,7 +153,17 @@ driver hiden_xcs_gen = {
   code write_function write_digital = {
    }
    code write_function write_twelve = {
-@  set par [expr int(4095.0 * ${par} / 100.0)]
+@  if { [hpropexists [sct] base] } {
+@    set base [sct base]
+@  } else {
+@    set base 0.0
+@  }
+@  if { [hpropexists [sct] span] } {
+@    set span [sct span]
+@  } else {
+@    set span 500.0
+@  }
+@  set par [expr int(${base} + (4095.0 * ${par} / ${SPAN}))]
 @  set cmd "${cmd_str}${par}"
   }
 #
@@ -129,4 +171,7 @@ driver hiden_xcs_gen = {
 #
   code mkDriver = {
   }
+  code chkrange_function = {
+    @ # hooked
+  }
 };