This manual describes the DDB (Direct Data Bus) function used to realize data input/output with a
CNC while running a program developed with the user PLC ladder language.
DDB includes the synchronous type (DDBS) and the asynchronous type (DDBA), but only the
asynchronous type will be explained in this manual.
DDB is a function that allows the PLC to directly read and write the various data in the CNC. By
setting the information required for reading and writing into the buffer and calling out the DDB function,
he PLC can set (write) the designated data into the CNC. Generally, the data is read and written in
one piece units, but data related to the control axis can be processed for the designated number of
axes.
Features of this function include that the read data can be referred to in the step immediately following
he execution of the DDBA command. This also applies to the written data.
(Note 1) Note that for the parameters, they may not be valid immediately after writing.
(Note 2) Even for the parameters that will be valid immediately after writing, displaying the screen
again may be required in order to reflect changes to the data displayed on the screen.
(Note 3) The functions related to the specifications not added to the NC cannot be used with the
DDB.
This manual is organized in the following manner after the first chapter. Please refer to the required
section for use.
6. Example of
DDB with
Ladder Circuit
5. Explanation of
Read/write
Data
4. Sub-section
No. List
3. Selection No.
List

2. Usage of DDB
Function with
ladder



输入输出电缆 FX-A32E-500CAB
晶体管输出模块 AJ65SBTB1-8TE
输入模块 FX2N-16EX-ES/UL
直流电抗器 FR-HEL-H45K
紧停开关导杆 GT16H-60ESCOV
晶体管输出模块 FX2N-16EYT-C
晶体管输出单元 FX2N-48ET-D
直流电抗器 FR-HEL-H1.5K
PLC FX1S-20MT-ESS/UL
网络模块 AJ71E71N-B2
输入输出模块 A0J2-E56AR
继电器输出单元 FX0N-40ER
连接电缆 AC06TE
编码器接头 MR-J3ENSCBL10M-L
输入输出模块 A0J2-E28AR
编码器用接头套件 MR-ENECNS
PLC FX2N-16MT-E/UL
小型CPU长距离连接电缆 GT15-C200EXSS-1
编码器用电缆 MR-ENECBL10M-H
模块 A1SJ71ME81
晶体管输出模块 AJ65VBTCE2-16T
PLC FX3U-48MT/ES-A
带以太网类型的Q系列CPU Q50UDEHCPU
编码器接头 MR-J3ENSCBL2M-L
DC 输入模块 AJ65VBTCE3-8D
PLC FX3G-14MT/ES-A
以太网接口模块 A1SJ71E71-B5-S3
脉冲输出模块 FX2N-1PG-E
速计数模块 QD62E
网络模块 A1SJ71QE71N-B5T