diff --git a/tcl/drivers/simramp.tcl b/tcl/drivers/simramp.tcl
new file mode 100644
index 0000000..94bf78f
--- /dev/null
+++ b/tcl/drivers/simramp.tcl
@@ -0,0 +1,71 @@
+# simulate a ramping device
+#
+
+namespace eval simramp {} {
+}
+
+proc stdConfig::simramp {{initvalue 0} {minvalue 0} {maxvalue 100} {time_const 60} {ramp 1e10} } {
+  variable name
+  
+  controller syncedprot 30
+  prop write stdSct::complete
+  
+  pollperiod 6 6
+
+  obj SIMRAMP_$name rd
+  default $initvalue
+  prop read simramp::poll
+  prop lasttime 0
+  prop minvalue $minvalue
+  prop time_const $time_const
+  
+  kids $name {
+    node set out
+    default $initvalue
+    prop check simramp::check_set
+    
+    node limit par $maxvalue
+    
+    node reg upd
+
+    node ramp par $ramp
+
+    node command par -text noop
+  }
+}
+
+proc simramp::check_set {} {
+  if {[sct target] > [hval [sct parent]/limit]} {
+    error "[sct] [sct target] is above limit ([hval [sct parent]/limit])"
+  }
+  sct update [sct target]
+}
+
+proc simramp::poll {{step 0}} {
+  set now [doubleTime]
+  set delay [expr $now - [sct lasttime]]
+  sct lasttime $now
+  set weight [expr 1.0 - exp(-$delay / double([sct time_const]))]
+  putIntoLimits delay 0 10
+  
+  get_values [sct] set reg ramp
+  set meas [hvali [sct]]
+  
+  if {$set > $reg} {
+    set reg [expr $reg + $delay * $ramp]
+    putIntoLimits reg [sct minvalue] $set
+  } else {
+    set reg [expr $reg - $delay * $ramp]
+    putIntoLimits reg $set 1e10
+  }
+  update_values [sct] reg
+
+  putIntoLimits reg [sct minvalue] $reg
+  set meas [expr $meas + $weight * ($reg - $meas)]
+  sct update $meas
+  eval "[hval [sct]/command] $meas"
+  return idle
+}
+
+proc noop {value} {
+}
diff --git a/tcl/simramp.addon b/tcl/simramp.addon
new file mode 100644
index 0000000..deb96d8
--- /dev/null
+++ b/tcl/simramp.addon
@@ -0,0 +1,3 @@
+addonDesc = simulate ramp
+
+makenv ramp -driver simramp 0 0 400 0.01 0.0166666666