diff --git a/Daqifi.Desktop.Test/Device/AbstractStreamingDeviceTests.cs b/Daqifi.Desktop.Test/Device/AbstractStreamingDeviceTests.cs
index 8ce2bdb3..7d23c52c 100644
--- a/Daqifi.Desktop.Test/Device/AbstractStreamingDeviceTests.cs
+++ b/Daqifi.Desktop.Test/Device/AbstractStreamingDeviceTests.cs
@@ -586,8 +586,8 @@ public void StartSdCardLogging_UsesCombinedAnalogMaskAndConfiguresDigitalPortsOn
             "Core handles this via the channelMask parameter.");
         CollectionAssert.Contains(
             device.SentCommands,
-            $"core:{ScpiMessageProducer.EnableAdcChannels("10101").Data}",
-            "Core should receive a single combined binary analog mask for the active SD logging channels.");
+            $"core:{ScpiMessageProducer.EnableAdcChannels("21").Data}",
+            "Core should receive a decimal channel mask for the active SD logging channels.");
     }
 
     [TestMethod]
diff --git a/Daqifi.Desktop/Device/AbstractStreamingDevice.cs b/Daqifi.Desktop/Device/AbstractStreamingDevice.cs
index dcfefa45..50dad990 100644
--- a/Daqifi.Desktop/Device/AbstractStreamingDevice.cs
+++ b/Daqifi.Desktop/Device/AbstractStreamingDevice.cs
@@ -473,7 +473,7 @@ public void StartSdCardLogging()
 
             // The Core package resumes StartSdCardLoggingAsync continuations on the caller's
             // synchronization context. Running it on the thread pool prevents UI deadlocks.
-            var channelMaskString = Convert.ToString((long)analogChannelMask, 2);
+            var channelMaskString = analogChannelMask.ToString(CultureInfo.InvariantCulture);
             Task.Run(() => coreDevice.StartSdCardLoggingAsync(channelMask: channelMaskString, format: SdCardLogFormat)).GetAwaiter().GetResult();
 
             IsLoggingToSdCard = coreDevice.IsLoggingToSdCard;