Rockwell Automation 1732E-OB8M8SR EtherNet/IP Dual Port 8-Point SOE Input and Scheduled Output Modules UM - Manual (Page 91)

Rockwell Automation Publication 1732E-UM003B-EN-E - March 2014 81
Use the Sequence of Events Input and Scheduled Output Modules Chapter 10
Use the Scheduled Output
Module The Motion Planner Output Cam (MAOC) instruction offers the functionality
to set and reset output bits based on an axis position.
Usage with MAOC Instruction
When used with motion and the MAOC instruction values in the output image
are controlled by the Motion Planner firmware in the controller, the Motion
Planner triggers the data to be sent to the module. Although, the normal
program/task scan also triggers data to be sent to the module. Data integrity is
maintained by the firmware always setting the sequence count for a given
schedule last.
When a programmed on or off event is detected, a schedule is sent to the output
module to turn the output on/off at the appropriate time within the next coarse
update period.
The Output Cam instruction divides the coarse update period into sixteen time
slots. For example, a coarse update period of 2
µs will yield sixteen 125 µs time
slots. Cam on/off events will be assigned to time slots based on their position
within the coarse update period. If both latch and unlatch events for a cam
element are assigned to the same time slot, they will cancel each other out. This
implies that the minimum pulse width of a cam element is greater than one time
slot.
The minimum pulse width of a cam element should be greater than the 100
µs
1732E-OB8M8SR minimum pulse width, or the 1/16 coarse update minimum
pulse width, whichever is larger.
The MAOC instruction detects latch and unlatch events one coarse update
ahead and schedules the event to occur within the next coarse update. This is
accomplished by applying a one coarse update internal delay to each scheduled
output latch and unlatch position. When the latch or unlatch event is detected,
the delta time from the start of the coarse update to the event is calculated, and
the output is scheduled to occur at the CIPSync corresponding to the next coarse
update period. To facilitate this, Output Cam functionality has access to the
CIPSync captured when the current coarse update period occurred.
The MAOC instruction is able to process scheduled output bits for the
1732E-OB8M8SR. The MAOC instruction sets the schedule mask bits that are
defined for use by the application.
IMPORTANT The 1732E-OB8M8SR Scheduled Output Module can be
associated with one (1) MAOC axis/execution target only.
IMPORTANT The outputs 0…7 can be forced by forcing the Data Bit to 0 or 1
and its corresponding bit in the ScheduleMask to 0.