Woodward 5466-258 Simplex Discrete I/O Module

Woodward 5466-258 Introduction

A Smart I/O module has its own onboard microcontrollers.

The modules described in this chapter are Smart I/O modules.

During the initialization of a smart module, the module's microcontroller turns the LED off after power-on self-tests have passed and the CPU has initialized the module.

The LED is illuminated to indicate an I/O fault.

The CPU also tells this module in which the rate group each channel is to run, as well as any special information (such as the type of thermocouple in the case of a thermocouple module).

At run time, the CPU then periodically broadcasts a "key" to all I/O cards, telling them which rate groups are to be updated at that time.

Through this initialization/key broadcast system, each I/O module handles its own rate-group scheduling with minimal CPU intervention.

These smart I/O modules also have on-card on-line fault detection and automatic calibration/compensation.

Each input channel has its own precision voltage reference.

Once per minute, while not reading inputs, the on-board microcontroller reads this reference.

The microcontroller then uses this data read from the voltage reference for both fault detection and automatic temperature compensation/calibration.

Limits have been set for the expected readings when the on-board microcontroller reads each voltage reference.

If the reading obtained is outside these limits, the system determines that the input channel, A/D converter, or the channel's precision-voltage reference is not functioning properly.

If this happens, the microcontroller flags that channel as having a fault condition.

The CPU will then take whatever action the application engineer has provided for in the application program.

A smart output module monitors the output voltage or current of each channel and alerts the system if a fault is detected.

Each I/O module has a fuse on it.

This fuse is visible and can be changed through a cutout in the plastic cover of the module.

If the fuse is blown, replace it with a fuse of the same type and size.

Woodward 5466-258 Installation

The modules slide into card guides in the control’s chassis and plug into the motherboard.

The modules are held in place by two screws, one at the top and one at the bottom of the front panel.

Also at the top and bottom of the module are two handles which, when toggled (pushed outward), move the modules out just far enough for the boards to disengage the motherboard connectors.

Woodward 5466-258 Troubleshooting

Each I/O module has a red fault LED, which indicates the status of the module.

This LED will help with troubleshooting if the module should have a problem.

A solid red LED indicates that the actuator controller is not communicating with the CPU module.

Flashing red LEDs indicate an internal problem with the module, and module replacement is recommended.

Woodward Module Description

Each Real-Time SIO Module contains the circuitry for three RS-485 ports.

Each port is designed to communicate with EM or GS/LQ Digital Actuator Drivers.

For each port, one driver is allowed for every 5 ms.

Each driver is identified by its address switches, which must match the driver number in the GAP application program.

The RS-485 communications to the Universal Digital Drivers can be used for monitoring or control purposes.

The Real-Time SIO Module features

5 ms update rate for critical parameters, with one driver per port

Digital Actuator Driver interface

Each RS-485 port may run in a different rate group

Communication fault detection for each driver, drivers with comm faults are disabled

Monitoring of driver parameters remotely

Configuration of driver parameters remotely

Allows a fast and very accurate position command (16 bits, no noise) for the drivers

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