From - Mon Jan 25 18:53:14 1999 Path: reader1.news.rcn.net!feed1.news.rcn.net!rcn!netnews.com!news.globix.net!nntp2.cerf.net!nntp3.cerf.net!mvb.saic.com!info-vax From: JOHN MALMBERG Newsgroups: comp.os.vms Subject: Re: HP plotter again Message-ID: <0095000003192775000002L052*@MHS> Date: Mon, 25 Jan 1999 18:06:28 -0500 Organization: Info-Vax<==>Comp.Os.Vms Gateway X-Gateway-Source-Info: Mailing List Lines: 50 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 Xref: reader1.news.rcn.net comp.os.vms:219661 Both the HP plotter and the VAXstations are DTE devices. You must use a null modem cable when connecting them up. Digital uses standard EIA signaling for their serial devices. I am assuming that HP is doing the same. The pinout for the MMJ connector is in many places, the OpenVMS FAQ is one of them. If you are converting a MMJ connector to a 25 pin connector, both the transmit and receive grounds of the MMJ side must be connected to pin 7 of the 25 pin connector. For VMS to hang when sending data out a serial port, some handshake must inhibit it. This could be either hardware, (again assuming that you chose a port that supports it) or software handshaking. The port settings must be set to be compatable with the serial device. For a 25 pin connectors, Note the gender much match the device. Pin 2 ----------------------- Pin 3 Pin 3 ----------------------- Pin 2 Pin 7 ----------------------- Pin 7 For DSR/DTR signaling Pin 6 ---------------------- Pin 20 Pin 20 --------------------- Pin 6 If DSR/DTR signaling is not used: Pin 6 --+ +- Pin 6 | | Pin 20 -+ +- Pin 20 For RTS/CTS signaling Pin 4 ---------------------- Pin 5 Pin 5 ---------------------- Pin 4 If RTS/CTS signaling is not used: Pin 4 --+ +-- Pin 4 | | Pin 5 --+ +-- Pin 5 For some devices that only use the TX and RX, lines the extra jumpers may not be needed. I find it safer to always put them on. -John