I don't have any more serial ports on my computer. What can I do?

Related Product(s): All HAL Software

Multi-port expansion boards allow a computer to obtain more serial ports than the computer originally came with. There are two different types you can buy. The first, which is less expensive, adds ports but each port requires a new IRQ (Interrupt Request). The second type gives you new serial ports but only requires one IRQ.

 

Several different companies manufacture the first type. You can find it at most computer stores, or you can order one through Sunbelt Industries. You can also order from Byte Runner Technologies. Visit their websites for pricing information.

 

To determine if you have enough Interrupt Requests (IRQs) – which get the attention of the CPU – you need to check the Windows Device Manager (Start > Settings > Control Panel > System > Device Manager). Once in the Device Manager, double-click on the first icon labeled "Computer." Once there you should have "Interrupt Request" selected. There is a list of numbers, called Settings, and the hardware that uses those settings. There are only 16 IRQs. If you want two more ports, you will need two IRQs. If you want four ports, you will need four IRQs, and so on. The numbers, which are IRQs, range from 00 to 15. Any setting that is not listed is an available IRQ and may be used for the expansion port board. For instance, if you have only two free IRQs, then you can only get a board that has two expansion ports. There is a way to have two different items of hardware use the same IRQ, but these items should not be used at the same time. For example, if you give your mouse and modem the same IRQ, then one or the other will lock up when you try to use them simultaneously. Unless you are an expert with computers and IRQs, we do not recommend this last solution as it can cause problems with your system if not configured correctly.

 

There is one additional possibility. Many of the hardware that HAL is compatible with will do multiple tasks that use only one serial port. These include:

• The Ocelot from Applied Digital, Inc. The Ocelot sends and receives Infrared signals and can also send and receive X-10 commands. In addition, the ADICON line of products from Applied Digital can be connected to the Ocelot to extend Input/Output control to HAL without using additional IRQs.
  
  
• The JDS TimeCommander Plus/Stargate and HomeBase Deluxe/HomeBase Pro systems. These will control X-10 and inputs/outputs through one serial port. You can also attach the compatible JDS Infrared Xpander for sending and receiving Infrared commands.
  
  
• The HAI Omni and OmniPro systems and the HSP Aegis will control your security system and the input/output functions.  They also have thermostats that are compatible with HAL.
  
  
• CSI HomeVision, which can control X-10, infrared, and inputs/outputs.