From 2a9e4f5a5b1b7a9ef6e3deaece03e93e08ceca24 Mon Sep 17 00:00:00 2001
From: Alessandro Candido <candido.ale@gmail.com>
Date: Mon, 20 Jan 2025 16:27:46 +0100
Subject: [PATCH] fix: Provide empty sequences for inactive channels

---
 src/qibolab/_core/instruments/qblox/cluster.py           | 4 +++-
 src/qibolab/_core/instruments/qblox/sequence/sequence.py | 6 ++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/qibolab/_core/instruments/qblox/cluster.py b/src/qibolab/_core/instruments/qblox/cluster.py
index 12e37ee15..e03a22640 100644
--- a/src/qibolab/_core/instruments/qblox/cluster.py
+++ b/src/qibolab/_core/instruments/qblox/cluster.py
@@ -118,7 +118,9 @@ def _prepare(
                 zip(chs, module.sequencers)
             ):
                 sequencers[slot][ch] = idx
-                config.sequencer(sequencer, address, sequences[ch], acquisition)
+                config.sequencer(
+                    sequencer, address, sequences.get(ch, Sequence.empty()), acquisition
+                )
 
         return sequencers
 
diff --git a/src/qibolab/_core/instruments/qblox/sequence/sequence.py b/src/qibolab/_core/instruments/qblox/sequence/sequence.py
index 8e449debe..a7b76f23e 100644
--- a/src/qibolab/_core/instruments/qblox/sequence/sequence.py
+++ b/src/qibolab/_core/instruments/qblox/sequence/sequence.py
@@ -58,6 +58,12 @@ def from_pulses(
             ),
         )
 
+    @classmethod
+    def empty(cls):
+        return cls(
+            waveforms={}, weights={}, acquisitions={}, program=Program(elements=[])
+        )
+
 
 def _split_channels(sequence: PulseSequence) -> dict[ChannelId, PulseSequence]:
     def unwrap(pulse: PulseLike, output: bool) -> PulseLike: