These cards are 24-bit parallel, digital input/output cards designed for use in PCI-Bus computers. The difference between the models is that I/O connections to PCI-DIO24D are via a standard 37-pin D-sub connector while I/O connections to PCI-DIO24H are via a 50-pin connector. The cards are 4.80 inches long (122 mm) and may be installed in any 5V PCI-bus slot in IBM and compatible personal computers.
These cards contain a type 8255-5 Programmable Peripheral Interface (PPI) chip. They can be programmed to accept inputs or to provide outputs on three 8-bit ports: designated Ports A, B, and C. Port C can be further divided into two 4-bit nibbles.
Each I/O line is buffered by a type 74LS245 tristate buffer transceiver capable of sourcing 15 mA. or sinking 24 mA. (64 mA. on request (74F245)). The buffers are configured under program control for input or output use according to direction control signals from the control register inside the PPI. Pull-ups (to 5 VDC) on the card assure that there are no erroneous outputs at power-up until the card is initialized by system software. Further, jumpers on the card provide a choice to either permanently enable the buffers or to tri-state them under program control.
Input/Output wiring connections for the PCI-DIO24D are via a 37-pin D-sub connector on the card mounting bracket. Either a 37-pin D-sub solder cup mating connector or an insulation-displacement ribbon cable can be used for I/O connections. Fused 5 VDC power is available at the I/O connector. A resettable on-board fuse is rated at 0.5A and can be reset by cycling computer power.
Input/Output wiring connections for PCI-DIO24H are via a 50-pin connector on the card mounting bracket. Insulation displacement ribbon cables can be used for I/O connections to termination panels such as ACCES' model STA-50 Screw Terminal card. The pin connections are also compatible with ACCES A24A , OPTO22, Gordos, Potter & Brumfield, etc opto-isolated module mounting racks. If needed for external circuits, fused 5VDC power is available at the I/O connector. The resettable 0.5A fuse can be reset by cycling computer power.
Optionally you can have one, two, or three 48-bit down counters configured as Event Counters. (See the Block Diagram which shows one 48-bit counter.) and can also be used as a Frequency source. To designate that you wish these counters, add -S01, -S02, and -S03 respectively to the model number. For example, a 24-bit digital input/output card with a 50-pin connector and one 48-bit counter is model PCI-DIO24H-S01.
The fused 5V output is available on all versions of the PCI-DIO-24D and H with the exception of the PCI-DIO-24D-S03. The -S03 on this card does not have 5V on the connector due to the limited number of pins on the DB37.