diff --git a/src/pv_controller/FromDevices.py b/src/pv_controller/FromDevices.py
index 089e5a6..2518d65 100644
--- a/src/pv_controller/FromDevices.py
+++ b/src/pv_controller/FromDevices.py
@@ -9,7 +9,7 @@ def floatAdaptor(i):
     return float(f"{i:0.2f}") if i else 0.0
 
 def onOffAdaptor(i):
-    return bool(i)
+    return 'on' if bool(i) else 'off'