Which products are affected?
ESP-DDS2-x (Global Drive PLC Developer Studio V2.x)
EVS93xx-EI (Servo PLC V1.x, V2.x)
EPL-10200 (Drive PLC all versions)
What happens?
In the online mode the current values for all variables displayed on the screen will be continuously read from the control and displayed. This process is called monitoring.
If one or several POUs or visualisation pages are opened in the DDS online mode, the following error message is indicated:
Number of monitor variables too big. Please close one window.
If a DDS project has been changed over from DDS V1.4 to DDS V2.x, this error message is already indicated if only a small number of variables is to be monitored.
When does the problem occur?
In Servo PLC V1.x and V2.x a buffer of 512 bytes is available for the monitoring of variables. Drive PLC V1.x up to V7.x has a buffer of 500 bytes. During the monitoring process the DDS ensures that the data volume for monitoring does not exceed this buffer size. In case of an error the error message mentioned above occurs.
In DDS V1.4 the data volume to be monitored has been set too big according to the Lenze default setting. Therefore the error message is indicated much later in DDS V1.4 than in DDS V2.x although the same DDS project is used.
Servo PLC V6.x has a buffer of 2048 bytes for monitoring purposes. This buffer is bigger than the buffer size set in DDS V1.4.
Possible diagnostics?
None.
Short-term measures/recommendations?
Reduce the number of variables to be monitored by closing windows (e. g. visualisation pages).
If a Servo PLC with version 6.x is used, changeover your DDS project to this new target system (tab Resources – Target settings). While the target system is changed over the settings made in the PLC configuration (tab Resources) are deleted. Re-enter the POUs used in the DDS project in the PLC configuration after the changeover.
Evaluation:
After DDS V1.4 has been changed over to DDS V2.x the number of variables to be monitored is smaller in case of the Servo PLC and Drive PLC target systems. This can mainly be noticed in case of extensive visualisation pages. The monitoring of variables is used for project planning, commissioning and remote maintenance. The program sequence within the PLC target system is not affected by this function restriction.
