Chapter 9 Changing Data Length Units To Byte Units (Word/Byte Units Setting) - Mitsubishi Electric MELSEC iQ-R Series User Manual

9
CHANGING DATA LENGTH UNITS TO BYTE
UNITS (WORD/BYTE UNITS SETTING)
The word units are used for the data length (count) of the amount of data transmitted/received using the following data
communication functions in data communication between C24 and target devices.
This chapter explains how to change the units (word  byte, byte  word) of the data length (count) transmitted/received with
the following data communication functions.
The data length units can be set for each C24 interface. C24 controls the number of data to be transmitted to the target device
and the number of data when it requests the CPU module to read the data received from the target device according to the
units set by the user.
Data communication functions and buffer memory affected by data length units
The following lists the data communications functions and buffer memory which are affected by the data length units.
(The buffer memory addresses in the table are the default value.)
Data communications function
MC protocol On-demand function
Nonprocedural protocol Data transmission
function
Data reception
function
Bidirectional protocol Data transmission
function
Data reception
function
How to change the units of the data length (count)
Change the units of the data length (count) by the either of the following methods.
• Changing with Engineering tool
Set "Word/byte units designation" to "Byte units".
Navigation window  [Parameter]  [Module Information]  "Module Name"  [Module Parameter]  "Basic Settings"
 "Various control specification"
• Changing by the CPU module
The units can be changed with the CSET instruction. (Page 520 Dedicated Instructions)
Name of buffer memory related to data length units
Data length designation (Un\G161/321)
Send data quantity designation (Un\G1024/2048)
Receive end data quantity designation (Un\G164/324)
Receive data quantity (Number of data for which read is requested)
(Un\G1536/2560)
Send data quantity designation (Un\G1024/2048)
Receive end data quantity designation (Un\G164/324)
Receive data quantity (Number of data for which read is requested)
(Un\G1536/2560)
9 CHANGING DATA LENGTH UNITS TO BYTE UNITS (WORD/BYTE UNITS SETTING)
9
Reference
MELSEC Communication
Protocol Reference
Manual
Page 52 DATA
COMMUNICATION
USING
NONPROCEDURAL
PROTOCOL
Page 86 DATA
COMMUNICATION
USING BIDIRECTIONAL
PROTOCOL
225