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1 GENERAL
This document specifies a subset of the Modbus serial communications protocol used to transfer data
between a master computer station and the PM130EH. The document provides the complete information
necessary to develop a third-party communications software capable of communication with the Series
PM130EH Powermeters. Additional information concerning communications operation, configuring the
communications parameters, and communications connections is found in "Series PM130EH
Powermeters, Installation and Operation Manual".
IMPORTANT
In 3-wire connection schemes, the unbalanced current and phase readings for power factor, active power,
and reactive power will be zeros, because they have no meaning. Only the total three-phase power values
can be used.
Most of the instrument advanced features are configured using multiple setup parameters that can be
accessed in some contiguous registers. When writing the setup registers, it is recommended to write all the
registers at once using a single request, or to clear (zero) the setup before writing into separate registers.