diff --git a/malcolm/modules/excalibur/parts/femdriverpart.py b/malcolm/modules/excalibur/parts/femdriverpart.py
index <HASH>..<HASH> 100644
--- a/malcolm/modules/excalibur/parts/femdriverpart.py
+++ b/malcolm/modules/excalibur/parts/femdriverpart.py
@@ -10,4 +10,4 @@ class FemDriverPart(StatefulChildPart):
     def report_configuration(self, context):
         child = context.block_view(self.params.mri)
         return [
-            NDArrayDatasetInfo(rank=2), UniqueIdInfo(child.arrayCounterReadback.value)]
+            NDArrayDatasetInfo(rank=2), UniqueIdInfo(child.arrayCounter.value)]
Made excalibur fem driver use array counter rather than readback since it deals with config, not state