General - Satec PM130 Reference Manual

1 GENERAL

This document specifies a subset of the Modbus serial communications protocol used to
transfer data between a master computer station and the PM130. The document provides the
complete information necessary to develop a third-party communications software capable of
communication with the Series PM130 Powermeters. Additional information concerning
communications operation, configuring the communications parameters, and communications
connections is found in "Series PM130 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.
Specification changes
The following indicates specification changes which apply to PM130 instruments with firmware
version 3.54 or later:
Added 32-bit long integer format for extended data registers (see Sections 4.2 and 5.8).
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