Introduction To Gpd 515 Modbus Rtu Communication; Standard Rs-232D Serial Communication - YASKAWA GPD 515/G5 Modbus RTU Technical Manual

Introduction to GPD 515 Modbus RTU Communication

This manual describes the set-up and protocol for Modbus Communication. The GPD 515 offers
RS-232D serial communication as a standard, and RS-485 as an option.
The Modbus RTU protocol requires that the controller communicates using a master-slave
technique, in which only one device (the master) can initiate transactions. The other devices (the
slaves) respond by supplying the requested data to the master, or by taking the action requested.
The GPD 515 drive must act in the slave mode.
A complete understanding of drive programming and operation is required before attempting
serial communication operation. A full discussion of programming and operation is covered in the
GPD 515 technical manual TM 4515.
GPD 515 / Modbus RTU Specifications
The data that may be sent or received from the drive consists of:
-Run Command
-Frequency Reference
-Fault Contents
-Drive Status
-Drive Parameter Settings
The following table illustrates whether the serial communication specifications are fixed or user
selectable. If the specification is fixed, the fixed value is shown in the last column. If the
specification is selectable, the range of allowed values is shown in the last column.
Communication Specification
Baud Rate
Data Bit
Parity
Stop Bit
Nodes
Nodes

Standard RS-232D Serial Communication

The GPD 515 drive offers RS-232D serial communications as a standard feature of the drive.
RS-232D has a maximum transmission distance of 50 feet. RS-232D only allows point-to-point
communications. The specifications for wiring and pin outs for RS-232D are given in Chapter 2.
1-2 GPD 515 and Serial Communication
Fixed or Selectable
Selectable
Fixed
Selectable
Fixed
RS-232D
Selectable for RS-485
Range
2400, 4800, or 9600 bps
8
None, Even, or Odd
1
point-to-point only
maximum of 31 nodes