diff --git a/common-tools/clas-detector/src/main/java/org/jlab/detector/decode/CLASDecoderPool.java b/common-tools/clas-detector/src/main/java/org/jlab/detector/decode/CLASDecoderPool.java
new file mode 100644
index 0000000000..744878b6aa
--- /dev/null
+++ b/common-tools/clas-detector/src/main/java/org/jlab/detector/decode/CLASDecoderPool.java
@@ -0,0 +1,45 @@
+package org.jlab.detector.decode;
+
+import java.util.concurrent.ArrayBlockingQueue;
+
+/**
+ *
+ * @author baltzell
+ */
+public class CLASDecoderPool {
+    
+    ArrayBlockingQueue<CLASDecoder> pool;
+
+    int sharedConstantsManagers = 64;
+
+    public CLASDecoderPool(int size, String variation, String timestamp) {
+
+        pool = new ArrayBlockingQueue<>(size);
+        
+        CLASDecoder d0 = null;
+        
+        for (int i=0; i<size; i++) {
+            
+            CLASDecoder d;
+            
+            if (i % sharedConstantsManagers == 0) {
+                d0 = new CLASDecoder();
+                if (variation != null) d0.setVariation(variation);
+                if (timestamp != null) d0.setTimestamp(timestamp);
+                d = d0;
+            }
+            else d = new CLASDecoder(d0);
+            
+            pool.add(d);
+        }
+    }
+
+    public CLASDecoder take() throws InterruptedException {
+        return pool.take();
+    }
+
+    public void put(CLASDecoder decoder) throws InterruptedException {
+        pool.put(decoder);
+    }
+
+}
\ No newline at end of file
diff --git a/common-tools/clas-reco/src/main/java/org/jlab/clas/reco/DecoderEngine.java b/common-tools/clas-reco/src/main/java/org/jlab/clas/reco/DecoderEngine.java
index 0d10debe60..319b5f9ca4 100644
--- a/common-tools/clas-reco/src/main/java/org/jlab/clas/reco/DecoderEngine.java
+++ b/common-tools/clas-reco/src/main/java/org/jlab/clas/reco/DecoderEngine.java
@@ -4,14 +4,13 @@
 import java.util.HashSet;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
-import java.util.concurrent.ArrayBlockingQueue;
-import java.util.concurrent.BlockingQueue;
 import org.jlab.clara.base.ClaraUtil;
 import org.jlab.clara.engine.Engine;
 import org.jlab.clara.engine.EngineData;
 import org.jlab.clara.engine.EngineDataType;
 import org.jlab.clara.engine.EngineStatus;
 import org.jlab.detector.decode.CLASDecoder;
+import org.jlab.detector.decode.CLASDecoderPool;
 import org.jlab.io.evio.EvioDataEvent;
 import org.jlab.io.hipo.HipoDataEvent;
 import org.jlab.jnp.hipo4.data.SchemaFactory;
@@ -28,8 +27,7 @@ public class DecoderEngine implements Engine {
         Clas12Types.EVIO,Clas12Types.HIPO,EngineDataType.JSON,EngineDataType.STRING);
 
     SchemaFactory schema;
-    BlockingQueue<CLASDecoder> pool;
-    int constantsShared = 64;
+    CLASDecoderPool pool;
 
     public DecoderEngine() {
         schema = new SchemaFactory();
@@ -58,21 +56,9 @@ public void destroy() {}
     @Override
     public EngineData configure(EngineData ed) {
         JSONObject json = new JSONObject(ed.getData());
-        pool = new ArrayBlockingQueue<>(POOL_SIZE);
-        CLASDecoder d0 = null;
-        for (int i=0; i<POOL_SIZE; i++) {
-            CLASDecoder d;
-            if (i % constantsShared == 0) {
-                d0 = new CLASDecoder();
-                if (json.has("variation")) d0.setVariation(json.getString("variation"));
-                if (json.has("timestamp")) d0.setVariation(json.getString("timestamp"));
-                d = d0;
-            }
-            else {
-                d = new CLASDecoder(d0);
-            }
-            pool.add(d);
-        }
+        pool = new CLASDecoderPool(POOL_SIZE,
+                json.optString("variation","default"),
+                json.optString("timestamp",null));
         return ed;
     }