diff --git a/site_ansto/instrument/config/environment/keysight_N8740A.sct b/site_ansto/instrument/config/environment/keysight_N8740A.sct
index 07d5c3d3..4be8daba 100644
--- a/site_ansto/instrument/config/environment/keysight_N8740A.sct
+++ b/site_ansto/instrument/config/environment/keysight_N8740A.sct
@@ -21,13 +21,26 @@ driver keysight_N8740A = {
       units = 'V';
     }
     var setpoint = {
-      readable = 1; read_command = 'SOURCE:VOLTAGE?';
-      writeable = 1; write_command = 'SOURCE:VOLTAGE ';
-      driveable = setpoint;
-      tolerance = 1;
+      readable = 1; fetch_function = read_setpoint; read_command = 'SOURCE:VOLTAGE?';
+      writeable = 1; write_function = write_setpoint; write_command = 'SOURCE:VOLTAGE ';
+      driveable = working_setpoint;
+      tolerance = 1; property settle_time = 5;
       lowerlimit = 0; upperlimit = 150;
       units = 'V';
     }
+    var ramp_rate = {
+      type = float;
+      value = 1.0;
+      units = 'V/S';
+      writeable = 1; write_function = write_direct;
+      lowerlimit = 0; upperlimit = 15;
+    }
+    var working_setpoint = {
+      type = float;
+      readable = 1; read_command = 'SOURCE:VOLTAGE?';
+      writeable = 1; write_function = write_direct;
+      units = 'V';
+    }
   }
   group current = {
     type = float;
@@ -76,4 +89,71 @@ driver keysight_N8740A = {
     set cmd "${cmd_str}${par}@@NOREPLY@@"
     @END
   }
+  code write_direct = {
+    @TCL
+    set cmd "@@NOSEND@@"
+    sct result ""
+    if { [sct target] != [sct oldval] } {
+      debug_log ${tc_root} 1 "[sct] changed to new:[sct target], from old:[sct oldval]"
+      sct oldval [sct target]
+      sct update [sct target]
+      sct utime readtime
+    }
+    @END
+  }
+  code write_setpoint = {
+    @TCL
+    set cmd "@@NOSEND@@"
+    sct result ""
+    sct ramp_start_time [sct utime]
+    sct ramp_start_value [hval ${tc_root}/working_setpoint]
+    sct ramp_rate_value [hval ${tc_root}/ramp_rate]
+    if { [sct target] != [sct oldval] } {
+      debug_log ${tc_root} 1 "[sct] changed to new:[sct target], from old:[sct oldval]"
+      sct oldval [sct target]
+      sct update [sct target]
+      sct utime readtime
+    }
+    @END
+  }
+  code read_setpoint = {
+    @TCL
+    if { [hpropexists [sct] target] } {
+      set target [sct target]
+      if { [hval ${tc_root}/working_setpoint] != ${target} } {
+        set elapsed_time [expr {[sct utime] - [sct ramp_start_time]}]
+        debug_log ${tc_root} 1 "read_setpoint elapsed_time = ${elapsed_time}"
+        if {[hpropexists [sct] ramp_rate_value] && [sct ramp_rate_value] > 0.0} {
+          set ramped_value [expr {[sct ramp_rate_value] * ${elapsed_time}}]
+          debug_log ${tc_root} 1 "read_setpoint ramped_value = ${ramped_value}"
+          if { ${target} > [hval ${tc_root}/working_setpoint] } {
+            set working_setpoint [expr {[sct ramp_start_value] + ${ramped_value}}]
+            debug_log ${tc_root} 1 "read_setpoint working_setpoint+ = ${working_setpoint}"
+            if { ${working_setpoint} > ${target} } {
+              set working_setpoint ${target}
+            }
+          } else {
+            set working_setpoint [expr {[sct ramp_start_value] - ${ramped_value}}]
+            debug_log ${tc_root} 1 "read_setpoint working_setpoint- = ${working_setpoint}"
+            if { ${working_setpoint} < ${target} } {
+              set working_setpoint ${target}
+            }
+          }
+        } else {
+          set working_setpoint ${target}
+          debug_log ${tc_root} 1 "read_setpoint working_setpoint  = ${working_setpoint}"
+        }
+        if {![hpropexists [sct] ramp_rate_value] || [sct ramp_rate_value] != [hval ${tc_root}/ramp_rate]} {
+          sct ramp_start_time [sct utime]
+          sct ramp_start_value [hval ${tc_root}/working_setpoint]
+          sct ramp_rate_value [hval ${tc_root}/ramp_rate]
+        }
+        set cmd "SOURCE:VOLTAGE ${working_setpoint}@@NOREPLY@@"
+        sct result [hval ${tc_root}/working_setpoint]
+      }
+    } else {
+      # cmd is fine
+    }
+    @END
+  }
 }