Checking The Performance Of Gm1 Controller; Performance Check Based On Cycle Time - Panasonic GM1 User Manual

9.8 Checking the Performance of GM1 Controller

The GM1-series motion controller is a system in which multiple tasks run. To ensure that the
GM1 controller operates as a system normally, CPU resources must be allocated to each task
properly. If CPU resources become insufficient, MotionTask and cyclic tasks cannot be operated
at the specified intervals. This section explains how to check task performance.

9.8.1 Performance Check Based on Cycle Time

The GM1 controller allows POU to be executed by allocating the POU to a task. To execute
POU normally, the processing time ("Average Cycle Time") of the task must be smaller than the
specified interval (*1) of the task.
*1: For "MotionTask", the specified interval is equivalent to the control cycle in "RTEX_Master".
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Task processing time
Task processing time can be viewed via the navigator pane and Task Configuration>Monitor.
In the following example, cycle times of "MotionTask" can be viewed.
If the control cycle of "MotionTask" is 1 ms, use the GM controller so that "Average Cycle Time"
is no more than xxx μs.
Even if "Average Cycle Time" is no more than the specified value, the cycle time may
temporarily increase if POU processing with a high load is executed in a particular cycle.
Temporary increase in the processing time can be viewed in "Max. Cycle Time". Because cyclic
communications are performed over the RTEX network, if the cycle time exceeds the task
interval, the RTEX command will not be updated in the next cycle, causing the commanded
position to remain the same as the previous value. (Missing RTEX command)
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Example of missing RTEX command
In the following example, missing RTEX command occurs because the cycle time of cycle n+1
exceeds the control cycle.
If "Max. Cycle Time" exceeds the control cycle of "MotionTask", the occurrence of missing
RTEX command will be indicated.
The occurrence of missing RTEX command can be checked in the following ways.
1. Checking in POU
Function block "RTEX_GetTrackingCommandError" can be used to monitor the occurrence
situation of missing RTEX command on the program.
For details on "RTEX_GetTrackingCommandError", refer to the GM1 Series Reference
Manual (Instruction).
2. Checking with GM Programmer settings
Using the task watchdog timer function makes it possible to check whether the cycle time
has exceeded the target value. In the example shown in the figure above, if time=1ms and
WUME-GM1RTXOP-01

9.8 Checking the Performance of GM1 Controller

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