Allen-Bradley POINT I/O 1734-VHSC24, User Manual, Page: 30 / 64

Publication 1734-UM003A-EN-P - August 2000
3-2 Very High Speed Counter Module Input and Output Data
Detailed Description of
Data Table Information Present Channel Data (Input Word 1)
This is a 32 bit unsigned long word value representing the current
count of the 24 bit counter
(configurations: count [0], x1 encoder [1],
x2 encoder [2], PWM [3], x4 encoder [4]) or the frequency
(configurations: period/rate [5], continuous/rate [6], rate measurement
[7])
. The range of values is 0
≤
value
≤
0x00FFFFFF (16,777,215).
Stored/Accumulated Channel Data (Input Word 2)
This is a 32 bit unsigned long word value representing the stored
count of the counter at the time of some specified event. In counter
configurations
(configurations: count [0], x1 encoder [1], x2 encoder
[2], x4 encoder [4]) without store modes selected, these words are not
updated. With store modes selected, they are the stored value of the
counter at the time of the specified event (ex: rising edge of Z input).
In
PWM [3] configuration it is the counter value at the end of the
period specified by the product of the time base x gate interval. In
period/rate [5]
and
continuous/rate [6]
configurations it is the total
accumulation of unscaled Z pulses (i.e. if scaling is set to 128, after
128 Z pulses the accumulator will increase by 128 counts).
The maximum frequency that accumulation can follow in these two
modes is 200Hz x scalar value (ex: 200Hz x 128 is 25kHz). Finally, in
Scalar
8-bit value used to divide the Z input by 2
n
Output Ties 0 0 0 0 0 T3 T2 T1 T0
Output Ties 1 0 0 0 0 T3 T2 T1 T0
Rollover Value 32-bit value at which the counter is commanded to rollover
Preset Value 32-bit value the counter is to be set to when CP is asserted
On Value 1 32-bit value that sets the compare window
Off Value 1 32-bit value that sets the compare window
On Value 2 32-bit value that sets the compare window
Off Value 2 32-bit value that sets the compare window
On Value 3 32-bit value that sets the compare window
Off Value 3 32-bit value that sets the compare window
On Value 4 32-bit value that sets the compare window
Off Value 4 32-bit value that sets the compare window
PWM Safe State Value 16-bit safe state value for the PWM signal
Counter Control SS Value 0 0 0 0 0 VR CP CR
Output Control SS Value DS ES OE FO DS ES OE FO
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 0