Around the 1990 time frame, I was working with a company that was part of a complicated system of communications satellite communications for the trucking industry. Originally, this was a cooperative venture between the satellite company and two companies that made the units that mounted in the trucks. The units used the Loran-C system to determine the truck's position, and communicated that, by default once an hour (but this was the companies were able to change that timing), and would allow the company to send short text messages to the drivers, and the drivers to send short text messages, mostly from a pre-programmed menu, back to head office. The company that I was working for got involved when one of the marketing people involved with one of the companies wanted a demonstration system with a graphical display. This was fairly advanced for the time, and so the equipment used for this system was quite expensive.
Oddly, the marketing and sales people found that companies willing to purchase the communication system itself, also demanded to be able to purchase the system that we produced, although the system that we produce was not intended as the overall management system for communications. It was, originally, intended merely as a demonstration of the system. However, in the way of customers and marketing everywhere, it turned out that people liked our graphical system much more than a simple database of messages. So, we tended to be a part of the purchase plan. The software which we sold to customers went for $5,000 per unit. It required a fairly advanced computer micro computer for the time, which cost about $5,000. So, anybody who bought this system was laying out at least $10,000 right away. In addition, in order to get an account with the satellite company, even before you started using it, companies were paying $50,000 a year. When they actually used the system there were additional charges, for each message that transited the satellite, including every position notification, as well as long distance charges for calling into the satellite company and picking up the data for your account. You will notice that this is before the internet was widely available: the companies simply had to do dial-up and connect with a modem. There wasn't really any available data network to ease the costs.
In addition to the cost for the software and the rather expensive computer to run it, users also required a fairly expensive modem. At a time when modems could be had for about $100, this particular modem cost $1,000. We also told people who are configuring the system and setting it up, that they required a full RS 232 cable.
So, as I say, this was a fairly expensive proposition.
We started to see some complaints by customers of the system, complaining that our system was telling them that an emergency message was coming in, but when they dialed in to get the emergency message, no emergency message was, in fact, delivered.
Eventually we found out what the problem was. When we specified a full RS 232 cable, we meant it. We used all 25 pins on an RS 232 connector. We assessed the status of the modem, and the call itself, the connection, and other factors. However, most people, having spent at least $11,000 for our system, and at least $50,000 for an account with the satellite company, then decided to save money on a $15 RS 232 cable, and would use any old terminal cable with an RS 232 connector. Very often these only had three pins connected.
The report of an emergency message was generated by reading one particular status line on the modem. This particular thing, on the RS 232 cable, was pretty much always unconnected when companies decided to use a two, three, or four wire terminal cable. Therefore, trying to read that status line indicated an emergency message, even if no emergency message was, in fact, being transmitted.
Previous: https://fibrecookery.blogspot.com/2024/05/mgg-516-hwyd-under-flight-path.html
Introduction and ToC: https://fibrecookery.blogspot.com/2023/10/mgg-introduction.html
Next: https://fibrecookery.blogspot.com/2024/05/mgg-518-hwyd-i-dont-have-to-admit.html
No comments:
Post a Comment