Digital Input Modules
Pulse I/O Module IOP335
Metso Automation MAX Controls Inc. • 277596 •
9-3
Mode 5 – Up/Down Pulse Timer
Counts corresponding to the on-time difference in input1 and input2.
The timebase frequency (0.5 usec/count) is counted up while
input1 = ON and counted down while input2 is ON.
Mode 6 – Pulse Width
ON time of last detected pulse in input1, based on the timebase
frequency (0.5 usec/count). Input2 is not used. The measurement
is updated at the end of each detected pulse (ON to OFF
transition). Counts read by DPU represent the average of the last
four measurements.
Mode 7 – Period
Time duration between the last onset of input1and the previous onset
of input1. The timebase frequency (0.5 usec/count) is counted
during this time. Input2 is not used. The measurement is updated
at the end of each detected period. Counts read by DPU represent
the average of the last four measurements.
Module Operation
This microprocessor based module supports up to 16 digital inputs. As
shown in the functional block diagram, the field circuits are used to detect
and optically isolate the digital inputs. High-speed optical isolators support
higher frequency inputs. The processor circuits implement the configured
timing functions and provide the interface to the I/O bus FPGA. The Time
Processor Unit (TPU) included in the 68332 processor is used to process the
timing functions. The TPU operates from microcode masked in 68332 ROM.
The 16 DI inputs are debounced in an FPGA and are available individually
to the processor TPU inputs.
Diagnostics
The module executes diagnostics on power up. To indicate any errors
detected during power-up or on-line operation the LED labeled active blinks
the first digit at a slower rate and the second digit at a faster rate.
During normal operation this LED stays on or flashes at a steady one-second
rate when the module is not being scanned. The diagnostic codes are as
follows:
To Next Page
Loading...