From 3c2c3b3180a3936dcf0cb4f094786f48319f69ad Mon Sep 17 00:00:00 2001
From: Dhanya Thattil <dhanya.thattil@psi.ch>
Date: Tue, 24 Mar 2026 11:20:37 +0100
Subject: [PATCH] throw approperiate error when no modules added for powers

---
 python/slsdet/powers.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/python/slsdet/powers.py b/python/slsdet/powers.py
index b71ff655f..b6f648f04 100755
--- a/python/slsdet/powers.py
+++ b/python/slsdet/powers.py
@@ -75,6 +75,8 @@ class DetectorPowers:
 
     @property
     def _powernames(self):
+        if self._detector.size() == 0:
+            raise RuntimeError("No modules added")
         # always get the latest list
         if hasattr(self._detector, 'powerlist'):
             return [n.replace(" ", "") for n in self._detector.powerlist]