diff --git a/ppp_install_jetson.sh b/ppp_install_jetson.sh
index 39c3f0e..618943e 100755
--- a/ppp_install_jetson.sh
+++ b/ppp_install_jetson.sh
@@ -173,6 +173,7 @@ do
 
 			# Devicename
 			sed -i "s/DEVICE/$devicename/" jetson_configure_modem.sh
+			sed -i "s/DEVICE/$devicename/" functions.sh
   
 			mv functions.sh $PPP_PATH
 			mv configs.sh $PPP_PATH
diff --git a/src/functions.sh b/src/functions.sh
index d3e28c7..fb22d49 100644
--- a/src/functions.sh
+++ b/src/functions.sh
@@ -10,6 +10,9 @@ CYAN='\033[0;36m'
 PURPLE='\033[0;35m'
 SET='\033[0m'
 
+# default arguments
+PORT=/dev/DEVICE
+
 function debug
 {
     ECHO_PARAM=${2:-''}
@@ -25,14 +28,14 @@ function check_network()
         NETWORK_OK=0
 
         debug "SIM Status: " "-n" # no line break
-        atcom AT+CPIN? | grep "CPIN: READY"
+        atcom -p $PORT AT+CPIN? | grep "CPIN: READY"
         SIM_READY=$?
 
-        if [[ $SIM_READY -ne 0 ]]; then  atcom AT+CPIN? | grep "CPIN:"; fi
+        if [[ $SIM_READY -ne 0 ]]; then  atcom -p $PORT AT+CPIN? | grep "CPIN:"; fi
 
 
         debug "Network Registration Status: " "-n" # no line break
-        NR_TEXT=`atcom AT+CREG? | grep "CREG:"`
+        NR_TEXT=`atcom -p $PORT AT+CREG? | grep "CREG:"`
         echo $NR_TEXT
 
          # For super SIM