Rockwell Automation 1794-IJ2XT FLEX I/O Frequency Input Modules User Manual User Manual
Page 48
Publication 1794-6.5.11 - September 2011
38 Read and Write Configuration Maps for the FLEX I/O Module
Word 4
Bits 00
Missing Pulse Alarm (channel 1) – Indicates that no Frequency input pulse has occurred within the period
determined by the Minimum Frequency Sampling Time and the Missing Pulse Multiplier. Primary control is
given to the Missing Pulse Multiplier to determine when this bit is set. However, if the Missing Pulse
Multiplier is set to 0, then the Minimum Frequency Sampling Time characteristics will determine when this
bit is set.
Bit 01
Wire Off Fault Alarm (channel 1) – when set, indicates that 24V DC Input (IEC 1+ or Switch Contact with
shunt) Wire Off Detection has gone true for any of the Frequency or Gate inputs on a channel that has the
Wire Off Fault Select = 1.
Bit 02
Frequency or Acceleration Alarm (channel 1) – Changes state from 0…1 if the calculated Frequency (actual
or scaled) exceeds the user programmed Maximum Frequency, or the absolute value of calculated
Acceleration/Deceleration exceeds the user programmed Maximum Acceleration Value.
The Frequency Alarm turns off when the Frequency drops below 95% of the Alarm Value.
The Acceleration Alarm turns off when the Acceleration drops below 90% of the Alarm Value.
Bit 03
Gate Input State (channel 1) – Indicates if there is a valid signal on the gate input. This parameter is only
determined once every 0.5…2 s.
Bits 04…05
Direction (channel 1) – Indicates the current Direction of Rotation, using both the Frequency and Gate
inputs. (Frequency leads Gate = Clockwise; Gate leads Frequency = CounterClockwise). Used for slow speed
detection from 1…1,500Hz. No or Stopped rotation can be determined by the state of the Missing Pulse
Alarm, when it is switched on. A missing Frequency Input generates a Missing Pulse Alarm, a missing Gate
Input only generates a No Sensor Present/Detected status (3).
Bits 06…07
Not used
Bits 08 (10)
Missing Pulse Alarm (channel 0) – Indicates that no frequency input pulse has occurred within the period
determined by the Minimum Frequency Sampling Time and the Missing Pulse Multiplier. Primary control is
given to the Missing Pulse Multiplier to determine when this bit is set. However, if the Missing Pulse
Multiplier is set to 0, then the Minimum Frequency Sampling Time characteristics determines when this bit
is set.
Bit 09 (11)
Wire Off Fault Alarm (channel 0) – When set, indicates that 24V DC Input (IEC 1+ or Switch Contact with
shunt) Wire Off Detection has gone true for any of the Frequency or Gate inputs on a channel that has the
Wire Off Fault Select = 1.
Bit 10 (12)
Frequency or Acceleration Alarm (channel 0) – Changes state from 0…1 if the calculated Frequency (actual
or scaled) exceeds the user programmed Maximum Frequency, or the absolute value of calculated
Acceleration/Deceleration exceeds the user programmed Maximum Acceleration Value.
The Frequency Alarm turns off when the Frequency drops below 95% of the Alarm Value.
The Acceleration Alarm turns off when the Acceleration drops below 90% of the Alarm Value.
Bit 11 (13)
Gate Input State (channel 0) – Indicates if there is a valid signal on the gate input. This parameter is only
determined once every 0.5…2 s.
Bits 12…13
(14…15)
Direction (channel 0) – Indicates the current Direction of Rotation, using both the Frequency and Gate
inputs.
Frequency leads Gate = Clockwise
Gate leads Frequency = CounterClockwise
Used for slow speed detection from 1…1,500Hz. No or Stopped rotation can be determined by the state of
the Missing Pulse Alarm, when it is switched on. A missing Frequency Input generates a Missing Pulse
Alarm, a missing Gate Input only generates a No Sensor Present/Detected status (3).
Bits 14…15
(16…17)
Not used
Bit/Word Definitions for Block Transfer Read Words
Word
Bit
Definition