diff --git a/das/src/main/java/com/das/modules/node/command/HeartbeatCommand.java b/das/src/main/java/com/das/modules/node/command/HeartbeatCommand.java
index b2ecf27b..4e1a3509 100644
--- a/das/src/main/java/com/das/modules/node/command/HeartbeatCommand.java
+++ b/das/src/main/java/com/das/modules/node/command/HeartbeatCommand.java
@@ -49,7 +49,7 @@ public class HeartbeatCommand implements BaseCommand{
                     JsonNode realNode = linkNode.get("real");
                     if (realNode != null){
                         boolean real = realNode.asBoolean();
-                        String key = String.format("link:%s:modbus", linkId);
+                        String key = String.format("link:%s:real", linkId);
                         ops.set(key, real, HEARTBEAT_TTL, TimeUnit.SECONDS);
                     }
                     JsonNode ftpNode = linkNode.get("ftp");