When characters are available on one or both of the serial ports, ttymon reads the characters into a buffer and writes them to the opposite port. Implementing ttymon The heart of ttymon () is the select call, which will wait on input from multiple file descriptors (see for more on select). It worked perfectly, and I solved the mystery. The modem connected my local host to the remote UNIX system, where I ran a communications program to the medical server. To solve my problem, I ran the vendor's program on my local PC, hooked that to one serial port on my local UNIX system, and ttymon'd that port (through a second port) to my modem. While it does this, it displays a log of the conversation. If ttymon reads characters from one port, it writes them to the other port. My solution was to develop the ttymon program, which uses two serial ports to monitor serial conversations. I needed to figure out how to monitor the conversation even though the server was at a remote location. This program would run on a PC and carry on a conversation with the server, and if I could monitor the conversation I could find out what 'my mistake' was. The vendor offered no advice, but did send me an MS/DOS-based surveillance program. The server product just wouldn't work to specifications (I was just shocked, of course). I followed the documentation's examples and, try as I might, all I could get the server to do was send back NAKs. There was only one problem: It didn't work. Those 4 'write' statements allowed me to quickly track down and fix a serial communication problem between two. Desired State Configuration (DSC) Planning Update – September. PSMDTAG:FAQ: How do I read/write data from a Serial Port? For information about how to read from a serial port in an. I had thorough documentation on the server's RS/232 protocol. The hospital and server were not local to my UNIX development host, but this in itself posed no problem I could connect the two computers via high-speed modems. My interface was supposed to connect to the server's RS-232 port. This server used an arrangement with a proprietary coax and an RS/232 port to perform real-time data acquisition from each bed. February 1996/The Poor Man's Serial Protocol Analyzer A Familiar Problem A few years ago, I was assigned a project to write an interface to a medical monitoring server, which connected many bedside medical monitors to a central surveillance unit.

Dsc Serial Protocol