diff --git a/lib/Insteon/Message.pm b/lib/Insteon/Message.pm
index bb9c32f26..57b54d576 100644
--- a/lib/Insteon/Message.pm
+++ b/lib/Insteon/Message.pm
@@ -254,6 +254,10 @@ sub send
                         		if $self->setby->debuglevel(1, 'insteon');
                         	$$self{no_hop_increase} = undef;
                         }
+                        
+                        # If No PLM-Receipt has been received for this message
+                        # then attempt to reconnect the PLM
+                        $interface->serial_restart() unless $self->plm_receipt;
                 }
 
                 # need to set timeout as a function of retries; also need to alter hop count
@@ -262,6 +266,10 @@ sub send
                     $self->setby->outgoing_hop_count($self->setby->default_hop_count)
                     	if $self->setby->can('outgoing_hop_count');
                 }
+                
+                # Clear PLM-Receipt Flag
+                $self->plm_receipt(0);
+                
                 $self->send_attempts($self->send_attempts + 1);
 		$interface->_send_cmd($self, $self->send_timeout);
 		if ($self->callback)
@@ -327,6 +335,22 @@ sub to_string
         return $self->interface_data;
 }
 
+=item C<plm_receipt()>
+
+Used to track whether the PLM has acknowledged receiving this message, either
+an ACK or NAK.  This is used to determine situations in which the serial
+connection to the PLM may have collapsed and may need to be restarted.
+
+=cut
+
+sub plm_receipt
+{
+	my ($self, $receipt) = @_;
+        $$self{plm_receipt} = $receipt if defined $receipt;
+        return $$self{plm_receipt};
+}
+
+
 =back
 
 =head2 INI PARAMETERS
diff --git a/lib/Insteon_PLM.pm b/lib/Insteon_PLM.pm
index 3021aff31..4b9686731 100644
--- a/lib/Insteon_PLM.pm
+++ b/lib/Insteon_PLM.pm
@@ -87,6 +87,25 @@ sub serial_startup {
 
 }
 
+=item C<serial_restart()>
+
+Attempt to restart/reconnect the serial port connection.
+
+=cut
+
+sub serial_restart {
+   my ($self) = @_;
+   my $instance = $$self{port_name};
+   my $PLM_use_tcp = $::config_parms{$instance . "_use_TCP"};
+   
+   # TCP Port gets reconnected elsewhere
+   return if $PLM_use_tcp;
+
+   ::print_log("[Insteon_PLM] WARN: The PLM did not respond to the last command."
+        ." The port may have closed, attempting to reopen the port.");
+   ::serial_port_open($instance);
+}
+
 =item C<new()>
 
 Instantiates a new object.
@@ -620,6 +639,9 @@ sub _parse_data {
         
         	# STEP 4b Is this a PLM Response to a command MH sent?      
         	if ($is_ack) {
+        	        #Note Receipt of PLM ACK
+        	        $pending_message->plm_receipt(1);
+        	        
         		::print_log( "[Insteon_PLM] DEBUG4:\n".
         	                Insteon::MessageDecoder::plm_decode($data)) 
         	                if $debug_obj->debuglevel(4, 'insteon');
@@ -676,6 +698,9 @@ sub _parse_data {
         		$data =~ s/^$ackcmd//;
         	}
                 elsif ($is_nack) {
+                        #Note Receipt of PLM NAK
+        	        $pending_message->plm_receipt(1);
+        	        
         		::print_log( "[Insteon_PLM] DEBUG4:\n".
         	                Insteon::MessageDecoder::plm_decode($data)) 
         	                if $debug_obj->debuglevel(4, 'insteon');
@@ -759,6 +784,9 @@ sub _parse_data {
         		$data =~ s/^$nackcmd//;
         	}
         	elsif ($is_badcmd){
+        	       #Note Receipt of PLM Bad Cmd
+        	        $pending_message->plm_receipt(1);
+        	        
         		::print_log( "[Insteon_PLM] DEBUG4:\n".
         	                Insteon::MessageDecoder::plm_decode($data)) 
         	                if $debug_obj->debuglevel(4, 'insteon');
@@ -910,6 +938,9 @@ sub _parse_data {
                         $data = substr($data, 12);
         	}
                 elsif ($record_type eq $prefix{all_link_record} and (length($data) >= 20)) { 
+        	        #Note Receipt of PLM Response
+        	        $pending_message->plm_receipt(1);
+                        
                         #ALL-Link Record Response
                         my $message_data = substr($data,4,16);
         		&::print_log( "[Insteon_PLM] DEBUG4:\n".Insteon::MessageDecoder::plm_decode($data)) 
@@ -962,6 +993,9 @@ sub _parse_data {
         		$data = substr($data, 6);
         	}
         	elsif ($record_type eq $prefix{plm_info} and (length($data) >= 18)){
+        	        #Note Receipt of PLM Response
+        	        $pending_message->plm_receipt(1);
+        	        
         		::print_log( "[Insteon_PLM] DEBUG4:\n".Insteon::MessageDecoder::plm_decode($data)) 
                                 if $self->debuglevel(4, 'insteon');
         	        
@@ -972,6 +1006,9 @@ sub _parse_data {
                         $data = substr($data, 18);
         	}
         	elsif ($record_type eq $prefix{plm_get_config} and (length($data) >= 12)){
+        	        #Note Receipt of PLM Response
+        	        $pending_message->plm_receipt(1);
+        	        
         		::print_log( "[Insteon_PLM] DEBUG4:\n".Insteon::MessageDecoder::plm_decode($data)) 
                                 if $self->debuglevel(4, 'insteon');
                         my $message_data = substr($data,4,8);