From 4f6c39836ca5eb2c594f065070bec0cd55b79769 Mon Sep 17 00:00:00 2001
From: bparks13 <bap@open-ephys.org>
Date: Wed, 24 Sep 2025 12:16:32 -0400
Subject: [PATCH 1/2] Round ReadSize property up to next multiple of 4

---
 OpenEphys.Onix1/StartAcquisition.cs | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/OpenEphys.Onix1/StartAcquisition.cs b/OpenEphys.Onix1/StartAcquisition.cs
index 88a90d25..f14c0acd 100644
--- a/OpenEphys.Onix1/StartAcquisition.cs
+++ b/OpenEphys.Onix1/StartAcquisition.cs
@@ -41,11 +41,14 @@ namespace OpenEphys.Onix1
     [Description("Starts data acquisition and frame distribution on a ContextTask.")]
     public class StartAcquisition : Combinator<ContextTask, IGroupedObservable<uint, oni.Frame>>
     {
+        int readSize = 2048;
+
         /// <summary>
         /// Gets or sets the number of bytes read per cycle of the <see cref="ContextTask"/>'s acquisition
         /// thread.
         /// </summary>
         /// <remarks>
+        /// <para>
         /// This option allows control over a fundamental trade-off between closed-loop response time and
         /// available bandwidth. A minimal value, which is determined by <see
         /// cref="ContextTask.MaxReadFrameSize"/>, will provide the lowest response latency, so long as data
@@ -55,10 +58,18 @@ public class StartAcquisition : Combinator<ContextTask, IGroupedObservable<uint,
         /// performance for high-bandwidth data sources. The optimal value depends on the host computer and
         /// hardware configuration and must be determined via testing (e.g. using <see
         /// cref="MemoryMonitorData"/>).
+        /// </para>
+        /// <para>
+        /// The number of bytes set will be rounded up to the next multiple of four.
+        /// </para>
         /// </remarks>
         [Description("Number of bytes read per cycle of the acquisition thread.")]
         [Category(DeviceFactory.ConfigurationCategory)]
-        public int ReadSize { get; set; } = 2048;
+        public int ReadSize
+        {
+            get => readSize;
+            set => readSize = (value + 3) & ~3; // NB: Round up to the next multiple of four to align with word boundaries in liboni
+        }
 
         /// <summary>
         /// Gets or sets the number of bytes that are pre-allocated for writing data to hardware.

From f5f62aa526c5180228443dd9851819f19d47448d Mon Sep 17 00:00:00 2001
From: bparks13 <bap@open-ephys.org>
Date: Mon, 29 Sep 2025 17:37:05 -0400
Subject: [PATCH 2/2] Update ReadSize documentation

---
 OpenEphys.Onix1/StartAcquisition.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/OpenEphys.Onix1/StartAcquisition.cs b/OpenEphys.Onix1/StartAcquisition.cs
index f14c0acd..86c0d556 100644
--- a/OpenEphys.Onix1/StartAcquisition.cs
+++ b/OpenEphys.Onix1/StartAcquisition.cs
@@ -60,7 +60,8 @@ public class StartAcquisition : Combinator<ContextTask, IGroupedObservable<uint,
         /// cref="MemoryMonitorData"/>).
         /// </para>
         /// <para>
-        /// The number of bytes set will be rounded up to the next multiple of four.
+        /// If a value is set that is not aligned to a 32-bit word boundary, it will be rounded up
+        /// to the next 32-bit aligned value.
         /// </para>
         /// </remarks>
         [Description("Number of bytes read per cycle of the acquisition thread.")]