RS232SendWaitfor.exe is a Serial Communication Utility that sends any string over the serial port and waits for a response for the specified number of milliseconds. It returns an error code denoting success or failure. The returned error code may be queried by a command (batch) file or from an application that spawns the utility. Example Usage: RS232SendWaitfor -b9600 COM1 2000 "AT\r" "OK\r" The above example can be used to detect a modem on a COM port. The example in the command file in the product documentation below shows how the error level can be queried to see if it was successful or not. Specifications: Compatible with Windows 7,Windows Vista, Windows XP, Windows 2003, Windows 2000, Windows NT Compatible with any COM port including USB/Serial adapters, Bluetooth/Serial Adapters, Ethernet/Serial Adapters as long as the export the COM interface Can be a command/batch file Can be spawned from any application Returns error code that may be queried. Possible Usage: Query for the presence of a mode. Query for the presence of equipment Send commands to equipments like lathes and other CNC machines. Many, many, many more.