Why the nvoDrvPwr readings are fluctuating below zero on ATV61 drive using Lonworks?
In ATV61 drive with Lonworks, the nvoDrvPwr parameter readings are sometimes fluctuating below zero into negative power (i.e. -1kW). The range of the SNVT is from 0 to -1. Because when power is negative, the SNVT shows the highest power value i.e. 6553.4 kW. How can the the range of Drive Power be adjusted into a negative number? It works on Modbus and BACnet protocols but Lonworks does not allow.
The scale is defined on a standard (LONMARK® Functional Profile: Variable Speed Motor Drive).
The solution is to use Scanner Input 1 (set the address of OPr on this register and read using the Lonworks variable nvoScannerIn1).
For more information, please see the file attached.