Jim, I have tried to talk to a Texas Instruments PLC using RS232. I had many troubles because some of their protocol included Enc & Ack as part of the Data String. I could never work around this. What I did was to use a RS232 to Digital Converter. It has 16 Digital lines that can be either sensed or switched via RS232 from the HP. It works well for my three projects, but may not for yours. I am controlling two conveyor lines and a small program to unlock two office doors using these converters. I have not tried to do this thru the terminal printer port, but use a ports from a DTC. So far the TI PLC is the only RS232 object that I have not been able to get to work. If the data stream protocol is more user friendly, you should be able to at least talk thru a DTC. I have been able to gather data from bar code readers, printers, a phone switch, digital converters, but not that darn TI. Steve Murphy Information Systems Manager Salem Division World Color [log in to unmask] ---------- From: Therm-O-Link[SMTP:[log in to unmask]] Sent: Wednesday, January 22, 1997 12:32 PM To: HP3000-L Subject: HP700 Terminals to PLC Knowledgable Listers: We are beginning a project to install HP 700 terminals (most likely /92's) at the operator station on our manufacturing lines. The terminals will connect to our HP3000 and present the operator with scheduled production for his/her shift. Part of the information presented will be product specifications. The line itself is controlled by Allen Bradley PLC's. We would like to link the PLC to the terminal (using the "printer" port on the terminal) and send commands to the PLC to control the manufacturing equipment. We will also receive data back from the PLC to record "events" in the manufacturing process. Has anyone ever done this? Assuming that the PLC's can receive/send ASCII data via RS232, what problems do you forsee in pursuing this project? Any other comments or questions? Jim Phillips Manager of Information Systems E-Mail: [log in to unmask] Therm-O-Link, Inc. Phone: (330) 527-2124 P. O. Box 285 Fax: (330) 527-2123 Garrettsville, Ohio 44231