To monitor (bi-directional) Serial communication RS-232 between two devices without physical cable, you can use the freeware Bill Serial Monitor. This freeware enable you to view, log, test and analyse the activity of the serial RS-232 port. If you want to monitor the serial protocol of two different serial devices you can use our Protocol Analyser function. DSR, CTS, DTR and RTS can also be controlled. Bill Serial Port Monitor is licensed as freeware, full size of the download is 3.76 MB. You may download a free version of Bill Serial Port Monitor by following download link at Free Download section of this page. Bill Serial Port Monitor is developed or distributed by SYMCOD INC and is listed under sniffers.