Woodward 5466-352 NetCon CPU 040 W-O LL Mem

Woodward 5466-352 NetCon CPU 040 W-O LL Mem

Intelligent I/O modules have their own onboard microcontroller. The modules described in this chapter are intelligent I/O modules.

When initializing an intelligent module, the module's microcontroller turns off the LEDs after the power-on self-test passes and the CPU initializes the module. The LEDs illuminate to indicate I/O faults.

The CPU also tells the module which rate group each channel will operate in, as well as any special information (such as the type of thermocouple in the case of a thermocouple module). While operating, the CPU then periodically broadcasts a "key" to all I/O cards, telling them which rate groups will 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.

When the onboard microcontroller reads each voltage reference, limits have been set for the expected readings. If the reading obtained is outside of these limits, the system determines that the input channel, A/D converter, or channel's precision voltage reference is not functioning properly. If this occurs, the microcontroller marks the channel as having a fault condition. The CPU then performs whatever actions the application engineer has provided in the application.

Intelligent output modules monitor the output voltage or current of each channel and alert the system if a fault is detected.

There is a fuse on each I/O module. This fuse is visible and replaceable through a cutout in the module's plastic cover. If a fuse blows, replace it with a fuse of the same type and size.