diff --git a/Machines/ILSOS_CCW_H52A/Datas/CellInfoScheduler.cs b/Machines/ILSOS_CCW_H52A/Datas/CellInfoScheduler.cs
index 0b7085b..f40e347 100644
--- a/Machines/ILSOS_CCW_H52A/Datas/CellInfoScheduler.cs
+++ b/Machines/ILSOS_CCW_H52A/Datas/CellInfoScheduler.cs
@@ -35,7 +35,14 @@ namespace ILSOS_CCW_H52A.Data
     {
         private readonly Logger _log = new Logger("CellInfoScheduler");
         public JigInfo Prefetch2 { get; private set; }  // 전전 셀: 셀 정보 수신, 업로드 전
-        public JigInfo Prefetch1 { get; private set; }  // 전 셀:  업로드 완료, 실행 중 / 완료 체크 대상
+
+        // volatile: Shift()에서 Prefetch1 = Prefetch2 대입이 release fence 역할.
+        // EncoderMonitor 스레드가 Prefetch1을 읽을 때 acquire fence로 JigNo 등 모든 필드 가시성 보장.
+        private volatile JigInfo _prefetch1;
+        public JigInfo Prefetch1 {
+            get => _prefetch1;
+            private set => _prefetch1 = value;
+        }
 
         /// 현재 보고 대상 JigInfo (CheckScannerListComplete에서 지정, 보고 완료 후 null)
         public JigInfo ReportTarget { get; set; }
diff --git a/Machines/ILSOS_CCW_H52A/Sequences/SeqAutoRunCCWH52A.cs b/Machines/ILSOS_CCW_H52A/Sequences/SeqAutoRunCCWH52A.cs
index abc42fc..349d214 100644
--- a/Machines/ILSOS_CCW_H52A/Sequences/SeqAutoRunCCWH52A.cs
+++ b/Machines/ILSOS_CCW_H52A/Sequences/SeqAutoRunCCWH52A.cs
@@ -964,7 +964,7 @@ namespace ILSOS_CCW_H52A.Sequences
                 var executeTarget = _CellScheduler.Prefetch1;
 
                 if (WeldingInPosition) {
-                    if (executeTarget != null && executeTarget.IsCanExist) {
+                    if (executeTarget != null && executeTarget.IsCanExist && executeTarget.JigNo > 0) {
                         Log.I($"Fork Before Min Rotate Encoder X : ({encoderX}), Encoder Y : ({currentAngle}), PLC Rotary : ({CurrentPosPLC}), List {executeTarget.ListNo}, JigNo : ({executeTarget.JigNo})");
                         if (!_SystemParameter.BypassModeLBAD) {
                             if (!executeTarget.CheckSendCellinfo) {