补充漏传文件

Cigarette/PLC/PLCDevice.cpp

@@ -7,7 +7,7 @@
 
 extern SysConf g_sys_conf;
 
-modbus_t * g_modbus;		//Modbus TCP
+modbus_t * g_modbus = NULL;		//Modbus TCP
 
 bool PLCDevice::init_plc(PLCDevice* PLCptr)
 {
@@ -28,9 +28,12 @@ bool PLCDevice::init_plc(PLCDevice* PLCptr)
 	return true;
 }
 bool PLCDevice::disconnect_plc(void)
+{
+	if(g_modbus)
 	{
 		modbus_close(g_modbus);
 		modbus_free(g_modbus);
+	}
 	return true;
 }
 int PLCDevice::write_bit_2_plc(int addr, int value)