DTC/Terminals garbled data, odd cursor behavior & disconnects.

[Nelson Laracuente]

Good morning,

Our company is slowly phasing out dummy terminals and DTC's but in the meantime we have approximately over 200 users that utilize these archaic devices. I am having a problem with some users getting garbled data, weird cursor behavior and some disconnects. I have looked at the datacomm settings, global and other settings and do not find anything out of the ordinary. I have gone in the DTC manager and cannot see that anything has been changed. I usually reset the DTC and these problems go away temporarily. I searched the web for some solutions and got some tips about garbled characters and disconnects. I revised in the DTC Manager the Network Timers to options that more identified with our network. I have tried accessing the NMMGR on the different HP3000's and they indicate that there are no DTC's configured. As to HP-UX which we have some users connecting to it and that is the main machine that most of these users are complaining I am not sure if anything needs to be tweaked at that end. The other problem is that we have an old DTC Manager HP Openview and we kind of inherited that thing to manage our DTC's. It is still functional but I have certain fears about the machine that it is housed. However, the latter is just some of the idiosyncrasies of the workplace. Anyone have any ideas? Thanks for your help.

[OldSchool]

Nelson,

It's been a long time since I've used a DTC but, as I recall, when we had problems it was caused by cabling issues. Pins 1,5,7,9? and the CTS signal was wired "on" at both ends, so their was no hardware pacing. Caused overruns and all kinds of garbage.

Long shot, and like I said, its been a long time (like 12-15 years)

scott

[Nelson Laracuente]

Thanks Scott. I will research and look into that. Have a great day Sir.

[Bill Hassell · Accepted solution]

> I am having a problem with some users getting garbled data, weird cursor behavior and some disconnects.

Did these connections ever work reliably in the past? How far is the terminal from the DTC (cable length)? Have the cables been rerouted over electrical conduits? You mau have a major increase in the electrical noise in the area and RS-232 cables are quite vulnerable to noise. Shorter, rerouted cables or put the cables into their own metal conduit.

> I have looked at the datacomm settings...

Are the terminals using 2 stop bits? That will help sync problems. Are they running at 9600 baud or faster? Try problem terminals at lower baud rates (2400).

> As to HP-UX which we have some users connecting to it and that is the main machine that most of these users are complaining I am not sure if anything needs to be tweaked at that end.

What terminals are they using? HP such as the 700/92 or 700/94, or similar? Do the users run them in HP mode or VT100 mode? Can the users get a shell prompt on the 9000? If so, have they been experimenting with their Unix for Dummies book? Displaying the contents of a binary file will easily garble the screen AND change terminal settings due to random codes in the data. Turn off the HP terminal, hold down the D key and turn the terminal on to reset. Then take away their shell access with a menu.

> I have certain fears about the machine that it is housed.

Is this an HP Vectra ES/12 running Windows 95? You definitely have reason to be worried. That combination had some terrible software that would not run on any other computer -- not just Win95 but specifically the ES/12. Once that machine dies, you will be crippled with what you have. I would have a disaster plan ready in case your management box blows up.

[Nelson Laracuente]

Bill,


Thank you for all the ideas. The terminals had intermittent times in which they worked ok and had issues. The distance on terminal from the DTC is probably under 75 feet. You are correct on the cables running over electrical conduit. Unfortunately there is no separation under the deck plates. My question there is shouldn't all the users experience issues if the lines are over electrical cables. It seems to be affecting 4 users out of over 50. For the most part all the terminals are at 9600, although we have experimented with that. I will try the problem terminals at a lower baud rate. For the most part all the terminals are at HP mode. They are all 700/96 terminals. As far as parity, they are all set for none/8. They do not have access to a shell prompt. They login to their designated application and have no access to anything else. The DTC Manager machine is W95 running HP OpenView for Windows Version D.00.01. I have no idea why we are even running this. Another idiosyncrasy of the workplace. Unfortunately, upper management does not want to upgrade or perform any DR for this application. I did indicate that if we lost that pc we would not have a way to manage the DTC's.

Bill, you certainly helped me out. I tried answering as much as I could your questions. I will look at and implement the items you suggested. Thank so much.