Rockwell Automation 1794-IP4 Series B FLEX I/O PULSE COUNTER User Manual - Manual (Page 13)

1–3 Overview of the Pulse Counter Module
Publication 1794ĆUM016B-EN-P - August 2002
The Pulse Counter module performs high-speed scaling calculation
operations for various industrial applications. The module interfaces
with a FLEX I/O family adapter which then communicates with a
programmable controller processor that has block-transfer capability
and external I/O devices.
The adapter/power supply transfers data to the module (block
transfer write) and from the module (block transfer read) using BTW
and BTR instructions in your ladder diagram program. These
instructions let the adapter read input values and status from the
module, and let you write output values and configure the module’s
mode of operation. The following illustration describes the
communication process.
ADAPTER
ACTIVE FAULT
LOCAL
FAULT
24VDC
POWER SUPPLY
RIO ADAPTER
1794ĆASB
AllenĆBradley
1
The adapter transfers your configuration data
to the module using a BTW.
Flexbus
External devices transmit
frequency signals to the modĆ
ule.
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 speciĆ
fied 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
OK
4 CH Pulse Counter Module
1
1794-IP4 AllenĆBradley
What the Pulse Counter
Module Does