diff --git a/code/application/source/sf_app/code/source/app/sf_service.c b/code/application/source/sf_app/code/source/app/sf_service.c
index 0604af114..0768909ee 100755
--- a/code/application/source/sf_app/code/source/app/sf_service.c
+++ b/code/application/source/sf_app/code/source/app/sf_service.c
@@ -91,15 +91,17 @@ SINT32 app_ttyusb_IsOpen(void) {
 
     UINT8 i = 0;
 
-    for (i = 0; i < 40; i++) {
+    for (i = 0; i < 150; i++) {
         if (access("/dev/ttyUSB2", F_OK) == SF_SUCCESS) {
             printf("tty usb ko exist!\r\n");
+            printf("4G Init OK\r\n");
             break;
         } else {
             usleep(100 * 1000);
-            if(39 == i)
+            if(149 == i)
             {
                 MLOGE("NO ttyUSB dev!!\n");
+                printf("4G Init ERR\r\n");
             }
         }
     }
@@ -119,6 +121,7 @@ SINT32 app_ttyusb_IsOpen(void) {
         {
             MLOGE("-------ttyUSB retry init fail!\n");
             s32ret = SF_TTY_ERROR_OPEN;
+            printf("4G Init Fail, retry\r\n");
             break;
         }
     }