Issue
Instructions and programming example for using SNVT_Switch as an input or output in Menta
Product Line
TAC Vista, EcoStruxure Building Operation
Environment
- Menta
- Function Block
Cause
The attached programming example is intended to clarify how to properly use SNVT_Switch in Menta.
SNVT_Switch is a structured SNVT with two attributes, or members, State and Value. Programmatically this will be one SNVT in the device template, but it will be programmed as two separate analog points in Menta. These two public blocks will have different names in Menta, but they will share the same SNVT name with the exception of one of the points being the state member, and the other being the value member.
It is important to remember that these points must always be programmed as analog points in Menta. AI's for input points, and AO's for output points. The state attribute is intended to be used for a binary on-off signal, but also contain the value -1 for Invalid value. The value attribute is intended to be used as a 0-100% signal.
This SNVT is typically used in the market for starting and stopping a VFD drive and sending a speed reference with the same SNVT. The 0,1 value on the state member will start and stop the drive, and the value member will send a 0-100% speed signal.
Resolution
Please see the attached Menta macro as a guide to using SNVT_Switch in Menta. This example shows you SNVT_Switch as an input and as an output to the Xenta controller.
To use this macro please follow these steps:
- Download the attached macro from above.
- Unzip the file and extract the SNVT_Switch.MTA from the archive to the local hard drive.
- Open Menta
- Right-click in Menta and click Load Macro
- Browse to the SNVT_Switch.MTA on the local hard drive and open it. It should import into the Menta file that is open.
