Printer for Mark 4


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Is it possible to use a modern laser printer for the control panel of a gas turbine Mark 4? How can this be realized?

>Is it possible to use a <b>modern</b> laser printer for the control
>panel of a gas turbine Mark 4? How can this be realized?

The reason <b>old</b> dot matrix printers are (still) used for Alarm Printers in many applications is because they print one line at a time--and most alarm messages are designed to be printed on a single line (when the printer resolution is set correctly).

In the 1980s and through the early 2000s such printers were called "line printers" and because they were usually connected to the parallel port of a PC the parallel ports were often labeled LPT or LPT1. (Some BIOS configurations still refer to parallel ports (when supplied) with the same nomenclature.)

I've checked for the better part of 30 years to find a more "modern" technology--and for the application (Alarm Printer, which prints one line of text at a time) there isn't anything I've found which is better.

If you could find a "modern" laser printer with a serial port, you could probably configure it to print the strings that come out of the Alarm Printer port/cable of a Mark IV. BUT, the "modern" laser printer isn't going to spit out a sheet of paper (because all "modern" laser printers use individual A4 or A-sized sheets of paper, sometimes larger) instead of fan-fold or rolled paper ONLY when the sheet is full. The alternative is to configure the printer to spit out a sheet of paper when a LINE FEED character is received (which is how most alarm strings are concluded)--and that would be a SERIOUS waste of paper.

While toner cartridges last longer than most printer ribbons, they are more expensive (in many cases more expensive than the printer itself!). So, buying printer ribbons and storing them in a proper environment is usually much cheaper in the short- and long run.

There's one more thing many people don't consider about trying to put a "modern" laser printer in a Mark IV turbine control panel (besides it likely won't fit): Electronically, laser printers are noisy. Both radiantly and on the AC mains cord. The AC mains cord noise isn't so critical in a Mark IV--but the high-frequency electromagnetic ("radio") waves emitted by the electronics of the "modern" laser printer can be just as disruptive as hand-held radios (and we ALL know how much problems those can cause a Mark IV!).

It's not about the age or vintage of the technology used for the Alarm Printer function (application). It's about the technology that works best for the function (application): a line printer is what the the Alarm Printer output was designed to work with. And, it really is the proper technology--regardless of age--for the application (function).

One of the problems with dot matrix printers in the Mark IV is that there really isn't proper space for a dot matrix printer. There isn't proper space for the fan-fold paper, and the rolled paper (mostly the roller for the output of the printer) is pretty touchy. If everything isn't properly aligned when the person changing the ribbon/paper or trying to read the alarms when they shove the drawer closed, the shock of shoving the drawer or of the door hitting the stops will usually cause the printer to shift position, and that is enough to screw everything up. (HINT: Use plastic blocks or pieces of rubber tubing securely glued to the bottom of the printer drawer to help keep the printer in place when the drawer is opened and closed--that will help keep things aligned and eliminate most of the paper jams.

Another problem with dot matrix printers in a Mark* turbine control system is that the Mark* usually spits out WAY TOO MANY alarms, causing the dot matrix printer to be using large amounts of paper at a fairly fast rate. That can most be attributed to operators not understanding how to use the LOCK- and UNLOCK ALARM functions of the Alarm Displays, as well as control technicians not properly attending to faulty sensors and circuits (eliminating nuisance alarms). Also, GE has a known propensity for generating a LOT of alarms even under normal circumstances, and many GE commissioning personnel even think it's normal and tell unsuspecting operators and their supervisors and plant technicians so, and it just becomes the truth (even though it's fake news). So, working to resolve nuisance alarms and prevent them from being annunciated can go a LONG WAYS towards reducing the number of alarms the "old" technology dot matrix printers have to print. And, training operators how to use LOCK ALARM and UNLOCK ALARM for those nuisance alarms until the technicians can resolve the problem can also be a great help.

But, as for changing printer ribbons and making sure the printer paper hasn't run out and is collected regularly--that's just something that operators are paid to do. A very large part of their job is Alarm Management--though most don't think that's true. And, in the case of Mark* turbine control systems with "old" technology dot matrix printers that's what they have to work with, unless and until someone makes a "new" technology line printer that works with fan-fold or rolled paper. Many Mark IV panels are located far from the central control room, and most operators don't want to go to the control compartments to check the printers/ribbons/paper on any kind of regular basis. But, they should--even if they don't want to; again, Alarm Management is part of the job of operator even if they don't like certain aspects of the task, it still has to be done. And, when there's no printed record of alarms when one is needed for troubleshooting, well, that can lead to trouble (which ALWAYS gets blamed on the Mark IV--even though it's NOT the Mark IV's fault!!!).

Some Mark IV owners have switched to using an inexpensive notebook PC with a serial port (or an older desktop PC with a serial port) and a communications program/app like MS-Windows HyperTerminal to collect the alarm strings from the Mark IV Alarm Printer output and save them to a text file. They can be displayed on the screen as they are received, and they can be printed to a "modern" laser printer connected to the PCs parallel or USB port when required. This, too, will take some training and procedures for the operators, but it's proven to be much more "acceptable" at many sites. One can also use serial "extenders" or "repeaters" to extend the cable from the Mark IV to a central control room where the operators don't have to go so far from their snacks and newspapers to check/change the printer ribbons and paper. And the same cable set-up could be used to connect to a PC in a central control room receiving and storing alarms on a hard drive.

Let us know if you find a suitable "modern" laser printer for use inside a Mark IV turbine control panel. One that uses rolled paper or fan-fold paper, one that has a serial port, one that fits in the space allotted, one that prints alarms one at a time and will spit out partial pages of alarms when necessary, and one that doesn't trip the unit with electromagnetic radiation. Until then, best to put everyone's heads at site together to come up with local solutions for keeping the printer in a stable location, keeping a supply of printer ribbons and paper in stock in a suitably-controlled environment, and keeping people regularly checking on the status of the printers and supplies. AND, resolving nuisance alarms, as well as teaching operators how to use LOCK- and UNLOCK ALARM to save paper and printer ribbon.

None of which is "modern" technology.