Yokogawa PR300 Power and Energy Meter - Manual (Page 9)

<Toc> <Ind> <1. Communications Overview >
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IM 77C01E01-10E
1. Communications Overview
1.1 RS-485 Communication Specifications
Protocols available for RS-485 communication interfaces include the PC link com-
munication protocol and the Modbus communication protocol.
Table 1.1 RS-485 Communication Specifications
Communication Hardware
Item Details Connected Device
2-wire system RS-485
PR201 original communication Personal computer etc. with SCADA
software installed to support PR201
original communication protocol
Compliant Standard
Protocol Specification EIA RS-485
PC Link Communication with
and without checksum
Modbus Communication
(ASCII and RTU modes)
A PC installed with a driver for PC link
communication and SCADA software,
PLC (FA-M3 UT link module), etc.
A PC installed with a Modbus driver
and SCADA software,
a Modbus-compatible PLC, etc.
2400 bps, 9600 bps, 19200 bps
1200 m
31
2-wire, half-duplex
Start-stop synchronization
Non-procedural
Shielded twisted pair cable
(AWG24-equivalent size)
Baud Rate
Maximum Communication Distance
Maximum Number of
Connectable Devices
Transmission Method
Synchronization
Communication Method
Communication Cable
1.2 Ethernet Communication Specifications
Protocols available for Ethernet communication interfaces include the Modbus/TCP
communication protocol.
Table 1.2 Ethernet Communication Specifications
Communication Hardware
Compliant Standard
Access Control
Protocol Specification
Baud Rate
Maximum Segment Length
Maximum Connecting
Configuration
Communication System
Data Format
Maximum Number of
Connections
Item Details
10BASE-T/100BASE-TX
Ethernet IEEE802.3
CSMA/CD
Modbus communication (Port No.: 502)
10 Mbps/100 Mbps
100 m *1
Cascade max. 4 levels (for 10BASE-T)
max. 2 levels (for 100BASE-TX) *2
TCP/IP
Binary
1
Connected Device
Ethernet-equipped PC etc.
*1: Distance between the hub and module.
*2: The number of hubs connectable in cascade configuration.