Omron CX-Programmer 9, Operation Manual

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PART 3: CX-Server Runtime
OMRON CHAPTER 6 – Performance Monitor Tool
Revision 2.0 CX-Server Runtime_Page 49
CHAPTER 6
Performance Monitor Tool
The Performance Monitor tool provides a facility to monitor system performance of active connections and can
also display the limits of performance against user instructions.
Particularly, it allows monitoring of communications. For example, a SYSMAC WAY connection configured at
9,600 baud, 7 data bits, even parity and 2 stop bits, transmits 10 bits per byte at 9,600 bits per second; this
means that the absolute maximum throughput of the cable is 960 bytes per second. Requesting or transmitting
data at this rate results in slow response times. The Performance Monitor tool has been engineered to show this
throughput figure for PLC connections.
The Performance Monitor tool can be set so that it is not obscured by other windows by selecting Always on top
from the Options menu.
To access the Performance Monitor tool select the CX-Server Performance Monitor tool from
the
Start pushbutton on the Microsoft Windows taskbar.
To close the Performance Monitor tool, select the Close button in the title bar.
The Performance tab displays an automated performance history and performance load for the selected active
connection in the Component option or for the overall performance. Details of activity are described in terms of
the number of open PLCs, active messages and open points in the Totals field.
The Statistics tab displays the number of bytes being transmitted and received by the selected active connection.
The limit to the number of characters that can be processed per second is described by the Theoretical CPS field.
The number of characters currently active is described by the Active CPS field. The PLC Average Latency (ms)
option shows how long it is taking the PLC to process the information in milliseconds.
Watching the Performance Monitor tool fluctuate between for example, 0% and 135%, indicates that it is
actually not possible to retrieve all the data requested in the time required according to the connected baud rate.
If the actual characters per second is greater than the theoretical maximum characters per second then
performance decreases. The performance load will fluctuate and the PLC average latency will increase. At this
point attention is required to the user instructions that are responsible for slowing performance.
The taskbar setting provides an at-a-glance indication of performance. The more the icon is
filled green, the greater the performance load. If the icon begins to fill red, then the actual
characters per second is greater than the theoretical maximum characters per second load.