If you are using a Parallel port card plugged into the motherboard in a PCI slot, or other compatible slot that interfaces directly to the microprocessor, you will need to make sure that the correct I/O address is entered into the configuration for your control software.
This I/O address is the first one in the range that Windows, or other operating system, will provide when accessing that information. In Windows, you would need to access this information in the device manager. Select the LPT port that is associated with the added parallel card. The port address will need to be in hex form, not decimal.
Other technical information that may help to understand the process:
The operating system will provide the address range, the first will be associated with pin 1, and the remaining addresses in the range will associate to the remaining pins (excluding the gnd pins) of the parallel port. This provides high and low signaling for each pin when a one is applied to the address. This is the reason the parallel port is called parallel, since each pin is independent and can output, or receive input simultaneously.
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I have installed PCI card parallel port and all pins read 3.5v no matter which jog key is pressed can you suggest a solution?