Digital488/32/OEM Measurement Computing Board-Level 32-Bit IEEE 488/Digital I/O Interface

The Measurement Computing / IOTech Digital 488/32/OEM IEEE488 to Digital I/O Interface Board is a board-level interface with the same capabilities as the Digital488.The Digital488/32/OEM's 32 TTL-level digital I/O lines are programmable in 4-bit ports as either inputs or outputs. When addressed to talk, the Digital488/32/OEM will output data from all thirty-two bits or a selected 8 bit port. The board also offers six handshake lines for implementing clear, data strobe, external data ready, inhibit, trigger, and SRQ functions. Its firmware includes a complete command set for facilitating the implementation of all its functions. This command set is identical to that employed by the other board-level and external interfaces in IOtech's industry-standard Digital488 family, facilitating quick prototyping and making the Digital488/32/OEM compatible with other Digital488 family units.

The Digital488/32/OEM is a digital input and output interface to the IEEE 488 bus. Each unit has 40 TTL level digital I/O lines, which are divided, into 5 eight-bit ports. Each port is software programmable as input or output. The Digital488 has several features, which give it versatile interface capability. A trigger output signal is asserted on the Group Execute Trigger (GET) command. Edge-triggered inputs can generate a Service Request on the bus. Six data formats are software programmable, including ASCII hexadecimal, ASCII character, ASCII binary, binary, high speed binary and ASCII decimal. There are also individual bit set and bit clear commands. Programmable terminators are provided to facilitate interfacing to various controllers.

A status mode enables the controller to interrogate the programmed status of the Digital488 at any time. A self-test is initiated at power-on which checks for proper RAM and ROM operation. When addressed to talk, the Digital 488 will output data from all forty bits or a selected 8-bit port. When addressed to listen, the unit will input data and programming information from the controller and output the data to the appropriate I/O port.