Publication 1794-6.5.11 - November 1997
Overview of the Frequency Input Module
1
-3
Typical Applications
You can use the 1794-IJ2 module in the power management, automotive,
food and beverage, and oil and gas industries for various flow and/or
turbine metering applications. Some sample applications include:
•
turbine shaft speed monitoring
•
automotive paint booths
•
brewery flow monitoring
•
petrochemical flow and custody transfer
ADAPTER
ACTIVE
FAULT
LOCAL
FAULT
24VDC
POWER SUPPLY
RIO ADAPTER
1794-ASB
Allen-Bradley
1
The adapter transfers your configuration data
to the module using a BTW.
Flexbus
External devices transmit
frequency signals to the module.
2
The module converts
frequency signals into integer
format and stores these values
until the adapter requests their
transfer.
3
Your ladder program instructs the
adapter to perform a BTR of the values
and stores them in a data table.
4
The adapter and module determine
that the transfer was made without error
and input values are within specified
range.
5
Your ladder program can use and/or move the data (if valid)
before it is written over by the transfer of new data in a
subsequent transfer.
6
Your ladder program performs BTWs to the module when you power
it up, and any time you wish to reconfigure the module.
7
FREQ
GATE
OK
0
FREQUENCY INPUT 2 CHANNEL
1
1794-IJ2
Allen-Bradley
F
0
F
FREQ
GATE
1
F
1
F
OUT
0
OUT
1