Chapter 3

Functional Details

82C55 emulation

The CIO-DIO48H emulates the 82C55 chip. The 82C55 emulation initializes all ports as inputs on power-up and reset. A TTL input is a high impedance input. If you connect another TTL input device to the output, it could be turned on or off every time the board is reset.

To establish a consistent TTL level at power-up, use resistors tied to either +5V (pull-up) or ground (pull- down). There are open locations for pull-up and pull-down resistor packs on the board.

Whenever an 82C55 emulation is powered on or reset, all pins are set to high-impedance input. Based on standard TTL functionality, these inputs will typically float high, and may have enough drive current to turn on external devices.

Consequently, if you have output devices such as solid state relays, they may be switched on whenever the computer is powered on or reset. To prevent unwanted switching, and to drive all outputs to a known state after power on or reset, pull all pins either high or low through a 2.2 K resistor.

Signal level control

To safeguard against unwanted signal levels, the devices being controlled by the CIO-DIO48H board should be tied low or high as required by a 2.2K Ω resistor. In a 2.2K eight-resistor SIP pack, one side of all of the resistors is connected to a single common point and brought out to a pin. The common line, usually marked with a dot or line, is at one end of the SIP. The remaining resistor ends are brought out to the other eight pins (refer to Figure 4).

2.2KOhm SIP

Dot indicates the common line

(LO or HI)

I/O Lines

Figure 4. Eight-resistor SIP schematic

Figure 5 shows a schematic of an SIP installed in both the pull-up and pull-down positions. Each port provides 10 holes in a line. The end labeled HI connects to +5V. The end marked LO connects to GND. The eight holes in the middle (n0 –n7) connect to the eight lines of the port (A, B or C).

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IBM CIO-DIO48H manual Functional Details, 82C55 emulation, Signal level control
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CIO-DIO48H specifications

IBM CIO-DIO48H is a cutting-edge, high-performance digital input/output card designed for industrial and commercial applications. This advanced component plays a crucial role in data acquisition and control systems, providing seamless communication between various devices within a network. The CIO-DIO48H is specifically engineered to handle multiple digital signals, making it an indispensable tool for automation and process control.

One of the standout features of the CIO-DIO48H is its capacity to support 48 digital I/O lines. This extensive input/output capability allows users to connect multiple sensors, switches, and other control devices simultaneously, thereby streamlining operations and improving efficiency in data collection. The board is equipped with 24 input and 24 output channels, providing ample flexibility for a wide range of applications.

The technologies integrated into the CIO-DIO48H significantly enhance its functionality and reliability. The use of high-speed FPGA (Field-Programmable Gate Array) technology enables real-time processing of digital signals, which is essential for applications requiring quick response times. This ensures that data is processed with minimal latency, making it ideal for time-sensitive automation tasks.

In addition to its robust processing capabilities, the CIO-DIO48H supports multiple communication protocols, including USB, Ethernet, and Serial. This versatility allows for easy integration with various systems and devices, enabling users to customize their setups according to specific requirements. The card is also compatible with a variety of operating systems, including Windows and Linux, ensuring broad accessibility for developers and engineers.

Another important characteristic of the CIO-DIO48H is its built-in support for hardware interrupts. This feature allows the card to signal when a change in input state occurs, eliminating the need for constant polling and freeing up system resources for other tasks. As a result, users can achieve more efficient and responsive data handling.

Furthermore, the CIO-DIO48H is designed with a rugged and compact form factor, making it suitable for deployment in both office and harsh industrial environments. Its durability ensures reliable performance over extended periods, reducing maintenance costs and downtime.

Overall, the IBM CIO-DIO48H combines high performance, flexibility, and reliability, making it an ideal choice for various applications in the automation and control sectors. Its advanced technologies and extensive features empower users to create efficient and effective systems tailored to their specific needs, paving the way for innovation and productivity in their operations.
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