Rockwell Automation 1794-VHSC 1794 FLEX I/O Very High Speed Counter Module User Manual - Manual (Page 53)

Rockwell Automation Publication 1794-UM010D-EN-E - July 2013 45
Communicate With Your Module
Chapter Summary In this chapter you learned how to communicate with your module. Read the
next chapter to learn how to interpret the module LED status indicators.
Words 16…19 Bits 00
01
02
03
04
05
06
07
Bits 08…15
(10…17) Output Ties – These bits connect the specified output to the appropriate compare window. There are 8 windows, 4 per
counter. Each output can be connected to any number of windows, from 1 to 8.
F1 = Tie output to first counter 1st window
F2 = Tie output to first counter 2nd window
F3 = Tie output to first counter 3rd window
F4 = Tie output to first counter 4th window
S1 = Tie output to second counter 1st window
S2 = Tie output to second counter 2nd window
S3 = Tie output to second counter 3rd window
S4 = Tie ouput to second counter 4th window
Set to 0.
Words 20…51 Bits 00…15
(00…17) Counter On and Off – These words program each of the 4 counter.s (first and second counter) on and off values. The
first compare window for each counter is used in PWM, and when programmed for PWM, the associated compare
window should remain at 0. The range of each entry is 0
≤
value
≤
16,777,215. When a tie is connected to a window
comparator, that window must be specified. These windows are always interpreted as counts, regardless of the
configuration setting, and can be computed as follows:
counts = (Scaler X 2.5E6)/desired frequency (for period/rate and continuous/rate)
counts = time base X desired frequency (for rate measurement)
Words 52…55 Bits 00…15
(00…17) Safe State Values – When the PLC transitions to PROG mode or a communication fault occurs, the module copies the
safe state words into its real time working buffer. The definitions are identical to the those in the counter control word,
except entering a PWM safe state value outside the range 0…9500 results in a Hold Last State.
Word 52 is Counter Control Safe State;
word 53 is Output Control Safe State;
word 54 is Channel 0 PWM Safe State
word 55 is Channel 1 PWM Safe State.
Configuration Word Definition
Configuration
Word Bit Definition