
Publication 1794-6.5.11 - November 1997
Writing Configuration to and Reading Status from Your Module with a Remote I/O Adapter
4
-3
Block Transfer Read Word Assignments for the Frequency Input
Module (1794-IJ2)
Bit/Word Definitions for Block Transfer Read Words
for the Frequency Input
Module
(Octal Bit)
17
16
15
14
13
12
11
10
07
06
05
04
03
02
01
00
Decimal Bit
15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00
0
Frequency 0 – 32,767 or 0.0 – 3,276.7 Channel 0
1
% Full Scale 0.0% to 3,276.7% Channel 0 or Acceleration –32,768 to +32,767 Channel 0
2
Frequency 0 – 32,767
or 0.0 – 3,276.7 Channel 1
3
% Full Scale 0.0% to 3,276.7% Channel 1 or Acceleration –32,768 to +32,767 Channel 1
4
R
R
Direction
Ch 0
GS Ch
0
F/A Ch
0
WO
Ch 0
MPA
Ch 0
R
R
Direction
Ch 1
GS Ch
1
F/A Ch
1
WO
Ch 1
MPA
Ch 1
5
Reserved
Diagnostic Status
Where:
GS = Gate state
F/A = Frequency/Accel alarm
WO = Wire-off alarm
MPA = Missing pulse alarm
R = Reserved
Word
Bit
Definition
Read
Word 0
Bit 00-15
(00-17)
Calculated value of Frequency (channel 0) – Frequency can be reported down to 1 or 1.0 Hz, depending on the
Frequency Range bit setting; below a 1 Hz value, 0 is reported; below a 1.0 Hz value, 0.0 is reported. Calculated
frequency depends on Minimum Sampling Time and Missing Pulse Multiplier.
Word 1
Bit 00-15
(00-17)
% of Full Scale or Acceleration (channel 0) – Value of the calculated Frequency scaled by the Maximum Frequency,
or Calculated Value of Acceleration in Hz / second, depending on the state of the Freq or Accel Alarm Select bit.
Note: % Full scale will be calculated accurately up to a maximum of 3,276.7%. Beyond this maximum, the value of
3,276.7% will be returned, and a “Calculation Failure” (9) will be set in the Diagnostic Status byte.
Word 2
Bit 00-15
(00-17)
Calculated value of Frequency (channel 1) – Frequency can be reported down to 1 or 1.0 Hz, depending on the
Frequency Range bit setting; below a 1 Hz value, 0 is reported; below a 1.0 Hz value, 0.0 is reported. Calculated
frequency depends on Minimum Sampling Time and Missing Pulse Multiplier.
Word 3
Bit 00-15
(00-17)
% of Full Scale or Acceleration (channel 1) – Value of the calculated Frequency scaled by the Maximum Frequency,
or Calculated Value of Acceleration in Hz / second, depending on the state of the Freq or Accel Alarm Select bit.
Note: % Full scale will be calculated accurately up to a maximum of 3,276.7%. Beyond this maximum, the value of
3,276.7% will be returned, and a “Calculation Failure” (9) will be set in the Diagnostic Status byte.