Dwyer PPM - Manual (Page 3)

MPM, APM, PPM, & LTI Series Modbus ® Register Tables Serial Communication
Page 3
Introduction
This document describes how to communicate with the MPM, APM, PPM, or LTI Series
of meters using the Modbus
® RTU Serial Communication Protocol. The user should be
familiar with Modbus serial communication and the meters. Refer to the meter instruction
manual and the serial communication adapters’ manual for setup and wiring instructions.
Go to
http://www.modbus.org/ to obtain a copy of the Modbus Specifications and to find
Modbus Technical Resources.
Note that although there are no specific 3x Registers, all 4x Registers are mirrored into
3x register space, and are therefore capable of being read by Modbus function 04 (Read
Input Registers).
Register Overview
40001 – 40047: Process Value (PV), Max PV, Min PV, Total, and Grand Total in floating
point and long integer formats, with interspersed relay status & digital I/O
status, for block reading; Start & Stop batch, Relay acknowledge, Reset
Max & Min, Reset Total, Grand Total & Batch count.
40051 – 40089: Manual control of relays, analog output, and digital outputs; Modbus
input display settings to use the meter as a Modbus display.
40101 – 40125: Input selection, Decimal points, totalizer settings, display settings, and
display intensity.
40126 – 40145: Adjust, RTD number to average, Filter & Bypass, Gate settings for pulse
input, Serial communication settings, Transfer function, Number of
points, Exponent, Round horizontal tank parameters, and Cutoff.
40152 – 40180: Function keys, Digital I/O, Passwords.
40181 – 40187: Dual-scale model: PV2 settings and PV2 value, PV1 Percent.
40301 – 40372: Relays; Set & Reset points, Turn-on & Turn-off delays, Operating Mode.
40401 – 40413: Analog output value and setup parameters.
41001 – 41129: Remote Scaling for 4-20 mA input.
42001 – 42129: Remote Scaling for voltage input.
43001 – 43129: Remote Scaling for pulse input.
44001 – 44129: Remote Scaling for 4-20 mA input PV2.
45001 – 45129: Remote Scaling for voltage input PV2.
49901 – 49908: Product ID and Firmware Version.
49999: Load Factory Defaults