Pulse Input Module
The pulse input (PI) module provides eight very sensitive, high-frequency inputs. It is optimized for use with nonamplified magnetic speed sensors common on rotating equipment such as turbines or compressors. The module senses voltage transitions from magnetic transducer input devices, accumulating them during a selected window of time (rate measurement). The resulting count is used to generate a frequency or RPM which is transmitted to the main processors. The pulse count is measured to 1 microsecond resolution.
The PI module includes three isolated input channels. Each input channel independently processes all data input to the module and passes the data to the main processors, which vote on the data to ensure the highest integrity.
Each module provides complete ongoing diagnostics on each channel. Failure of any diagnostic on any channel activates the Fault indicator, which in turn activates the chassis alarm signal. The Fault indicator merely indicates a channel fault, not a module failure. The module is guaranteed to operate properly in the presence of a single fault and may continue to operate properly with certain kinds of multiple faults.
The pulse input module supports hotspare modules.
