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Successor to SA / SR series



I heard that the SA / SR-20 series has been abolished.
Which successor should I choose?



Since the command word system and hardware configuration are fundamentally different between the SA / SR series and the current S series PLC, there is no direct compatibility, But You can convert SA / SR series programs to S series programs using “Direct Converter”. It can be converted to a series of programs.

The SA / SR series was a stage type and a ladder type, and there were two types of CPUs, but the S series is integrated.

“Direct Converter” can be downloaded free of charge from our website.

Please select the successor model considering the I / O points, mainly for the SU, D2, and SJ series.

Note: SA-20 and SR-20 cannot be connected to a PC, so “Direct Converter” cannot be used.


Rough procedure

1) Determine the PLC series after replacement.

2) Determine the array of PLC I / O modules after replacement.

3) Read the ladder program of SA / SR series you are using now.

* Since the communication module (E-03DM) cannot be used with SA-20 / SR-20,

The ladder program cannot be read to the personal computer.

Sorry for your inconvenience, but visually read by the programmer (A-21P / R-21P)

Please manually enter in DirectSOFT 5.0J Build 34.

Next, replace the CPU with SA / SR-21 and write the ladder program with DirectSOFT.

The procedure after that is the same as SA / SR-21.

4) Convert the ladder program so that it can be used in the replaced PLC.

5) Replace the PLC.

6) Write the ladder program to the replaced PLC.

7) Check the operation.

Things to prepare

Please install Direct Converter and KPP in your PC in advance.
Click here to download Direct Converter
Click here to download KPP

2) Communication cable. (Between PC-SA / SA series and PC-PLC after replacement)

Determine the PLC after replacement

1) D2 series / SU series / SJ-ETHER are candidates for the replaced CPU.

Each has its strengths / weaknesses.

Please refer to the table below and the simple comparison table to select a replacement model.

PLC candidate for replacement Maximum size(mm) Ease of wiring Maximum number of I/O points Cost performance I / O module comparison table
D2 series 370W x 90H x 92D 16-point I / O requires change of crimp terminal 1536 Click here for comparison table
SJ-ETHER 304.4W x 85.0H x 86.7D It is necessary to change the crimp terminal 142 Click here for comparison table
SU series 441W x 150H x D 2048 Click here for comparison table
【Reference Information】
SA/SR series
465.0W x 120.0H x 136.0D 168

Please see here for the programming of the PLC after replacement.
Click here for details on the specifications of the D2 series.
Click here for details on the SJ series specifications.
Click here for details on SU series specifications.
Click here for details on the SA series specifications.
Click here for details on the SR series specifications.

2) Check the wiring cable length and the PLC installation space after replacement.

-The I / O sequence of the SA / SR series is from right to left, but the PLC after replacement is the opposite from left to right.

Check if the length of each cable is sufficient.

-Check if it is necessary to redo the power cable and I / O cable tip processing.

3) Determine the I / O module array of the PLC after replacement.

Read the SA / SR series ladder program and convert it for the successor model

1) Connect the SA / SR series PLC to a personal computer.
Please see here for the connection procedure.

2) Create a folder to save the conversion file in advance.

3) Start Direct Converter.

* Direct Converter uses either COM1 / COM on the personal computer side.

If COM1 / COM2 has already been used on another device, change the settings of your computer so that either COM1 / COM2 can be used.

4) Upload (read) the ladder program with Direct Converter.

Please see here for the upload (read) procedure.

5) Allocate the I / O of the PLC after replacement.

6) Convert the ladder program. Save the ladder program.

7) Save the ladder program and exit Direct Converter.

8) Start KPP.

9) Import the file (***. Kpg) saved in 6).
Please see here for the import procedure.

10) Change the PLC model to the replaced PLC.

11) After conversion, save the ladder program (project).
For detailed procedure, please refer to the procedure manual here.

Write the ladder program to the replaced PLC and check the operation.

Click here for the connection procedure with the PLC after replacement
 Click here for D2 series
 Click here for SJ series
 Click here for SU series
Click here for the ladder program writing procedure.


The SA / SR series has different mnemonics for the replaced PLC and ladder program.

There are some parts that cannot be converted correctly with DirectConverter.

Please make sure that there is no difference between the program before conversion and the program after conversion.

If you have any questions regarding replacement, please feel free to contact us.


Related manual

Related keywords


Previous SA-20 / SR-20 Connection with PC
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