Rockwell Automation 1794-IJ2XT FLEX I/O Frequency Input Modules User Manual User Manual
Page 53
Publication 1794-6.5.11 - September 2011
Read and Write Configuration Maps for the FLEX I/O Module 43
Word 3
Bits 00…01
Wire-Off/Missing Pulse fault select mode (channel 0) – Sets the mode for 24V DC IEC 1+
Wire Off Input Detection and Missing Pulse Detection result for any input (Frequency or
Gate). The Maximum Frequency is determined by Frequency Range bit and the
Maximum Frequency value, and the Minimum Frequency is determined by Frequency
Range bit. The Wire Off detect time (in mode 1, 2, & 3) is 2 seconds maximum.
Bit
01
00
Channel wire-off/missing pulse detection mode
0
0
Disabled
0
1
Alarm only (frequency unchanged)
1
0
Alarm and force frequency to maximum frequency value
(32767 or 3276.7 or maximum frequency value, 0).
1
1
Alarm and force frequency to minimum frequency value (0 or 0.0).
Bits 02…03
Missing pulse delay multiplier bits (channel 0) – Specifies the number of Missing Pulse
Alarms periods (Minimum Frequency Sampling Times) which is permitted before the
alarm is raised, if enabled. Used to defeat the Missing Pulse Alarm during a system
startup.
Default = 0 – No multiplier; alarm generated immediately (normal mode with 2 s
extension delay)
Bit
03
02
Alarm periods before alarm generated
0
0
No multiplier; alarm generated immediately (normal mode with 2 s
extension delay)
0
1
2 sample periods + 2 s delay before alarm
1
0
8 sample periods + 2 s delay before alarm
1
1
32 sample periods + 2 s delay before alarm
Bit 04
Frequency or Acceleration Alarm Select (channel 0) – Determines if the value in the
Maximum Frequency or Acceleration write word is a Frequency (actual or scaled) or
Acceleration Alarm value. If set to Frequency, Acceleration is not calculated.
0 = Frequency alarm
1 = Acceleration alarm
Default = 0 – frequency alarm
Bits 05…06
Acceleration Calculation Time (channel 0) – Specifies the number of Frequency Sample
Times over which the module calculates acceleration.
Default = 0 – Rolling Average (previous 4 samples)
Bit
06
05
Acceleration Calculation Time in Frequency Sample Times
0
0
Rolling Average (previous 4 samples)
0
1
8
1
0
16
1
1
32
Bit 07
Initiate Startup Select (channel 0) – Alerts a channel that if process start up is in
progress to defeat the missing pulse alarm for a time determined by the missing pulse
delay multiplier.
0 = Normal Run Mode;
1 = Startup Mode – defeat/delay Missing Pulse Alarm
Default = 0 – Normal Run Mode
Bit/Word Definitions for the Block Transfer Write Words
Word
Bit
Definition