diff --git a/site_ansto/instrument/config/environment/temperature/pfeiffer_hg.sct b/site_ansto/instrument/config/environment/temperature/pfeiffer_hg.sct
index c7eac615..39bb4b70 100644
--- a/site_ansto/instrument/config/environment/temperature/pfeiffer_hg.sct
+++ b/site_ansto/instrument/config/environment/temperature/pfeiffer_hg.sct
@@ -30,12 +30,15 @@ driver pfeiffer_hg = {
 
   code pid_function pid_pressure = {
 @    if { [hpropexists [sct] pid_control] } {
-@      hsetprop [hgetpropval [sct] pid_control] pid_bias ${pid} 
-@        if { [hpropexists [hgetpropval [sct] pid_control] target] } {
-@          hset [hgetpropval [sct] pid_control] [hgetpropval [hgetpropval [sct] pid_control] target]
+@      set co [hgetpropval [sct] pid_control]
+@      if { !([hpropexists ${co} pid_bias] && [hgetpropval ${co} pid_bias] == ${pid}) } {
+@        hsetprop ${co} pid_bias ${pid}
+@        if { [hpropexists ${co} target] } {
+@          hset ${co} [hgetpropval ${co} target]
 @        } else {
-@          hset [hgetpropval [sct] pid_control] [hval [hgetpropval [sct] pid_control]]
+@          hset ${co} [hval ${co}]
 @        }
+@      }
 @    }
   }
 
@@ -61,6 +64,9 @@ driver pfeiffer_hg = {
 
   code write_function setPoint = {
 @    sct pid_control /sample/tc9/Valve/Setpoint
+@    sct update [sct target]
+@    set cmd "@@NOSEND@@"
+@    set nextState "idle"
   }
 
   code mkDriver = {