Yokogawa PR300 Power and Energy Meter - Manual (Page 62)

<Toc> <Ind> <4. PC Link Communication Protocol>
4-1
IM 77C01E01-10E
4. PC Link Communication Protocol
4.1 Overview
The use of PC link communication enables the PR300 to communicate with a device
such as a PC or FA-M3(PLC)'s UT link module. Such a device can be used in commu-
nication to read/write data from/to D registers which are internal registers of the
PR300.
PLC
FA-M3
Model of UT link module: F3LC51-2N
RS-485 communication
Maximum communication distance: 1200 m
Maximum number of slave stations to be connected: 31
Figure 4.1 Example of Connection for PC Link Communication
Hereafter, PCs are generically called “higher-level devices.”
In PC link communication, a higher-level device identifies each PR300 with a station
number of 01 to 99.
NOTE
• The PR300 has data (D register) the unit of which is two words. When 2-word data
need to be written or read, writing or reading operations must be performed for the 2-
word data at the same time.
• Even if data written to the D register is out of the effective range, a normal response is
returned. The part of the written data within the effective range becomes effective on
the PR300 when the equivalent setup change status is written for that data.