What would multiple serial ports be used for?

I saw someone was using something like the card in the link below on there system for some networking gear on their pc. I am very curious what a person would need 8 serial ports for. What kind of stuff uses this?

http://www.newegg.com/Product/Product.aspx?Item=N82E16815124041&cm_re=serial_card--15-124-041--Product

Solution 1:

Point of Sale systems use something like this a lot of the time. I used to work for a company who would have the UPC Scanner, a scale and some other input devices all running into the one card via the multi connection cable.

Solution 2:

Industrial and test equipment often uses serial ports. For example in the manufacturing facility where I work there are serial connections to meters, power supplies, signal generators, and the equipment under test. The test station must communicate with all these devices to run automated production tests.

SCADA Systems, which perform wide area data gathering and control, often communicate with field devices over serial connections, or using radios with serial connections.

Although Ethernet connections are becoming more common, there's still a lot of equipment with serial ports. Sometimes this is less expensive to make, sometimes it uses less power than LAN connections, sometimes the devices are older and LAN connections weren't common.

Solution 3:

We used to use them for simultaneously downloading the logs off 8 GPS flight data recorders for gliding competitions. There's an unusual one for you... :)

Solution 4:

I work in a company that supplies a moving map and sensor management system for offshore systems like oil rigs and boats. We tend to use these kind of things to provide multiple inputs from GPS, AIS, output to dataloggers and alternative sites (where ethernet is not available) as well as input from our own proprietary transponders.