diff --git a/config/devices.properties b/config/devices.properties
index 87119e7..4bf545d 100644
--- a/config/devices.properties
+++ b/config/devices.properties
@@ -41,3 +41,4 @@ oa=ch.psi.pshell.epics.Motor|X04SA-ES3-XPS:OMEGAA|||true
 #sixch=ch.psi.pshell.device.MotorGroupBase|alpha delta gamma omegaH nu phi|||
 fourcv=ch.psi.pshell.device.MotorGroupBase|alpha delta gamma omegaV|||
 $energy=ch.psi.pshell.epics.Positioner|X04SA-DCM:E X04SA-DCM:E-READ|||true
+transm=ch.psi.pshell.epics.ControlledVariable|X04SA-ES2-FI:TRANSM-SET X04SA-ES2-FI:TRANSM|||
diff --git a/script/device/Mythen.py b/script/device/Mythen.py
index 2b41dde..861757a 100644
--- a/script/device/Mythen.py
+++ b/script/device/Mythen.py
@@ -8,8 +8,10 @@ class Mythen(DeviceBase, Readable):
     def set_acquire_time(self, value):
         caput(self.prefix + ":cam1:AcquireTime", float(value))
 
-    def get_acquire_time(self):
-        return caget(self.prefix + ":cam1:AcquireTime_RBV", 'd')
+    def get_acquire_time(self, readback = True):
+        if readback:
+            return caget(self.prefix + ":cam1:AcquireTime_RBV", 'd')
+        return caget(self.prefix + ":cam1:AcquireTime", 'd')
 
     def set_threshold(self, value):
         caput(self.prefix + ":cam1:ThresholdEnergy", int(value))