dave@sea375.UUCP (David A. Wilson) (10/22/88)
I have an application running under 4.3BSD, Xenix, Microport and Venix systems that uploads data from a barcode scanner to a disk file. The scanner is cordless and will transmit its contents when inserted in a holder that is connected to an RS232 port on the host. The holder contains an optical receptor, so it can only receive data from the scanner. Therefore, no flow control is possible on the transmitted data. The holder contains only a circuit to convert the optical data stream to RS232 ascii data, too bad. :-( I know that the maximum amount of data that can be transmitted from the scanner is 32K. The scanner can transmit at up to 9600 baud. I currently set it to use 1200 baud, since higher rates cause data to be lost by overruns. I would like to be able to use the higher rates to reduce the uploading time. All systems are multi-user so system loads fluctuate. What solutions are like to yield best results? Lowest cost? Most reliable? Most portable? Most transparent to applications? 1. Install special device driver that can handle the maximum amount of data in a single read. 2. Install hardware buffering box to collect all data and upload it with flow-control to the host.(Any recommendations here?) 3. Tuning tty driver parameters for lowest overhead. I do not have access to source on anything OS than 4.3BSD Unix. Ideas welcome, David A. Wilson uw-beaver!tikal!slab!sea375!dave -- David A. Wilson uw-beaver!tikal!slab!sea375!dave
davidsen@steinmetz.ge.com (William E. Davidsen Jr) (10/27/88)
In article <223@sea375.UUCP> dave@sea375.UUCP (David A. Wilson) writes: | I have an application running under 4.3BSD, Xenix, Microport and Venix systems | that uploads data from a barcode scanner to a disk file. You're going to kick yourself. Stop trying to solve the problem at the UNIX end and make the hardware honor the flow control! Go buy a serial to serial printer buffer which accepts flow control. I had one with a 64k buffer from Black Box, and literally threw it away because I hadn't used it in a year. I'm sure there are other companies making similar products. -- bill davidsen (wedu@ge-crd.arpa) {uunet | philabs}!steinmetz!crdos1!davidsen "Stupidity, like virtue, is its own reward" -me
richard@neabbs.UUCP (RICHARD RONTELTAP) (10/27/88)
(Sorry, can't quote) Have you thought about using an intelligent I/O board. There are available with 512K of memory, so data loss would be *very* unlikely, if not impossible. For IBM/PC/AT/386 type machines there are a number of good boards available. I wouldn't know about your BSD machine. (A VAX?). We use an Intellicom 16-port board, working great! Richard (...!mcvax!neabbs!richard)