NS-Series Programmable Terminal Performance Tips
This article provides tips with details that improve performance of an NS-Series Programmable Terminal.
NS-Series HMIs offer high performance with fast response for typical machine applications, but some unique project configurations can slow screen switching and object response. Understanding and avoiding these conditions during development can optimize performance and increase the overall quality of the application.
The following sections detail known circumstances that reduce operation speeds:
Alarm/Events and Objects
The NS Series Programming Manual (Cat. No. V073) states that the maximum number of alarms and events that can be registered for one project is 5,000. This maximum capacity can be taxing on the unit and cause subsequent slowed response. When an alarm is registered, the NS always monitors the host (PLC) address. This can cause excessive communications, especially when the NS project contains hundreds of objects, screens or any combination thereof.
Always keep the number of Alarms and Events to a minimum to optimize communications between the NS and the Host (PLC). As an example, a project with the following conditions created a slow page change response:
- Approximately 9,500 objects such as ON/OFF buttons, word lamps, numeral display & inputs, string display & inputs, multifunction objects and alarm/events.
- About 4,500 of these objects were alarm/events*
*Note: When the number of alarm/events was reduced by 50% to ~2,200, responsiveness became fast and acceptable.
Additionally, the NS Series Programming Manual (Cat. No. V073) also states that "The communications speed may be reduced if consecutive addresses are not set in the Alarm/event Setting Items Dialog Box under Alarm/event setting. Set consecutive addresses if the communications speed is slow."
Multifunction objects allow multiple processes to be executed with the press of a button, such as controlling system bits, PLC addresses and switching screens simultaneously. These objects require additional communication and processing resources of the NS and should be used in a limited capacity when creating an NS project. As an example, a project with the following conditions created a slow page change response:
- 12 multifunction objects on one screen*
*Note: When the multifunction objects were reduced and replaced with lamps, bitmaps and command buttons, responsiveness became fast and acceptable.
Many incremental improvements have been created for the NS-Series HMI. These improvements can be realized by ensuring your System Version is up to date. Recent improvements include screen switching performance enhancements. CX-Designer software includes instructions detailing the System Version update/recovery procedure. These instructions are installed in the same directory as CX-Designer and can typically be found in C:\Program Files (x86)\OMRON\CX-One\CX-Designer\HowToRecoverUpdate.pdf.
To optimize the performance of the NS-Series HMI, please adhere to the following recommendations when creating a project:
*These details and references were made at the time of the NS-series system version 8.6. Newer versions may function differently.