Allen-Bradley POINT I/O 1734-VHSC24, User Manual, Page: 34 / 64

Publication 1734-UM003A-EN-P - August 2000
3-6 Very High Speed Counter Module Input and Output Data
Pulse Width Modulation (PWM) Value (Output Word 3)
When the module is programmed for a PWM [3] configuration, the
time base is enabled, the counter, rollover the 1
st
ON and 1
st
OFF
value for the respective channel are used. Ties can be used to direct
the PWM signal to any or both outputs. The range of PWM values is 0
≤
value
≤
9500 decimal (i.e. 0.00%
≤
value
≤
95.00%). Entering a value
“below” 0 will result in a PWM of 0%; a value greater than 9500 will
result in a PWM of 95.00%. The actual duty cycle observed at the
output will depend on the turn on and turn off times of the MOSFET,
the energy storage capability of the cable/load and the resistance from
output to return.
Configuration Data The following represents the configuration data used by the
1734-VHSC24 module.
Counter Configuration (Configuration Word 1)
Use this byte to select the type of counter desired.
07 06 05 04 03 02 01 00
ZI MD CF Counter 0
0 0 0 0 Counter
0 0 0 1 Encoder X1
0 0 1 0 Encoder X2
0 0 1 1 PWM
0 1 0 0 Encoder X4
0 1 0 1 Period/Rate
0 1 1 0 Continuous/Rate
0 1 1 1 Rate Measurement
0 0 0 Store Count Disabled
0 0 1 Mode 1 - store/continue
0 1 0 Mode 2 - store/wait/resume
0 1 1 Mode 3 - store, reset/wait/start
1 0 0 Mode 4 - store, reset/start
1 0 1 Reserved
1 1 0 Reserved
1 1 1 Reserved
0 Z input - 0 = not inverted
1 Z input - 1 = inverted