The Verran AC Data Link and DPS

f your technical control center is like mine, one of your more common probI lems is cabling an assortment of personal computers operating as network management consoles to printers. A second associated problem is finding space to house a ’who’swho’ of printers accumulated over the years as you added consoles to control leased line modems, dial-in modems, DSUs or NTUs, data PBXs, digital access and cross-connect systems, and other monitoring and control products. What may have started out as controlled growth often changes into a free-for-all, with printers inserted into the first available bay and then cabled to the newly installed console which is usually placed in a common area to facilitate its use and visibility. Within a period of time, it probably becomes exceedingly difficult to install additional printers as the time and effort required for cabling starts to resemble a nightmare. Thus, your first inclination is to consider the use of fallback switches. Although printers connected to monitoring and control consoles are not heavily used, when a requirement arises to obtain a hardcopy you rarely want to walk 20 or 30 metres to throw a fallback switch. Even when used, most fallback switches are of the A-B or A-B-C type, limiting the sharing of one printer to two or three consoles which must be cabled to the switch. Thus, any vendor that develops a product which allows a large number of consoles to dynamically share the use of a printer without requiring the use of cables should find a receptive market for their product. Now that I have pontificated on the need for a cableless printer sharing device, let’s focus our attention upon the subject of this column-the Verran AC DataLink and DPS printer sharing units. Although the use of these products is not actually cablefree, they eliminate the necessity of cabling your console’s printer port to a printer. In addition, the wellthought-out features of this set of products enables printer output from consoles to be buffered and printed one after the other with form feeds used to separate qu’eued printer output. Buffer storage permits many moderate-sized print jobs to be immediately serviced, freeing non-multitasking consoles for performing other functions. Form feed generation separates print jobs, enabling a required output to be rapidly located and separated from other printed material. As the product names at the beginning of this column imply, two separate devices are normally required to share a printer-a DataLink and a DPS, the latter an acronym for dedicated printer sharer. The DataLink is first cabled to your console’s printer port. Next, an electrical cable with one end permanently connected to the DataLink is plugged into your AC power outlet. Similarly, additional DataLinks are cabled to the printer ports of other consoles and their electrical cables are plugged into other electrical outlets. At the printer to be shared, you would cable the DPS data cable to the Centronics socket interface of the printer, while its electrical cable would be simply inserted into another electrical outlet. By transmitting data over power, up to seven DataLinks can be used to access one DPS device, enabling seven consoles to share the use of a common printer.