Selecting a replacement PLC for an existing legacy PLC
Due to technological advancement and other market forces, some older models of OMRON PLCs are discontinued from production. OMRON typically provides maintenance support for discontinued PLCs for seven years after the discontinuation date and advises that users of systems with discontinued PLC models replace them with modern PLCs.
In order to facilitate these replacements, please consult the below decision tree to determine the appropriate replacement model. Note that in some cases, direct replacements may not exist or be discontinued as well. In such cases, the closest viable replacement will be given, with any significant differences or reprogramming requirements listed. It is recommended to carefully consider the replacement PLC's capabilities, and to contact your OMRON representative if unsure about any aspect of such a replacement.
What is the model series of the existing PLC in the system?
The recommended replacement for an existing CP1E PLC is a CP2E PLC.
Replacing a CP1E with a CP2E is a relatively simple matter. Note the below points for advice on how to select the exact PLC model, and for any differences between the existing and replacement PLC.
- The model number of the new PLC will closely match the existing PLC. For example, a CP1E-E20DR-A is replaced with a CP2E-E20DR-A. There are some exceptions to this, but matching the number of built-in I/O (the 20 in both of the mentioned model numbers) will provide a shortlist of models to pick from.
- CP1E PLCs have a depth dimension of either 85mm or 79mm, depending on the exact model. CP2E PLCs have a depth of 80mm. All other dimensions are the same.
- CP1E PLCs use USB to connect to a computer for programming. The CP2E-N models use ethernet.
- CP1E-N models possess a built-in serial port, using a D-sub connector. CP2E PLCs do not normally have built-in serial ports, with the exception of the CP2E-S models, which have a serial port using a terminal block.
For other details, and a guide on carrying out this replacement, please see the below linked document.
Users of the CS1 series should be aware that the CS1 series are relatively older PLCs, and may experience extended lead times when acquiring certain products.
Users of the CS1 series should be aware that the CS1 series are relatively older PLCs, and may experience extended lead times when acquiring certain products.
Users of the CS1 series should be aware that the CS1 series are relatively older PLCs, and may experience extended lead times when acquiring certain products.
The recommended replacement for an existing CPM PLC is a CP1E PLC. However, the CP1E PLC series is also discontinued, with the recommended replacement being a CP2E PLC.
There are significant differences between the CPM series of PLCs and the CP2E series of PLCs, which are summarised below.
- The body colour of a CPM PLC is bone, while the CP2E is black.
- CPM PLCs map their built-in outputs from channel 10, while CP2E PLCs map built-in outputs from channel 100.
- The physical depth of the CP2E is larger than most equivalent models of CPM PLCs. Other dimensions are the same.
- Programming, connection and power methods are all significantly different.
For further details, and guides on replacing CPM PLCs with CP1E PLCs, please see the below links. Note that replacing a CPM PLC with a CP2E PLC will require using the below links in combination with the CP1E to CP2E replacement guide, which is also provided below.
CPM1A to CP1E Replacement Guide
The recommended replacement for an existing CS1D-*S PLC is a CS1D-*SA PLC.
Users of the CS1 series should be aware that the CS1 series are relatively older PLCs, and may experience extended lead times when acquiring certain products.
The CS1D-*S and CS1D-*SA PLC model ranges are very similar in terms of specifications and features. To replace a specific CS1D-*S, please refer to the below table.
| Existing PLC | Replacement PLC |
| CS1D-CPU42S | CS1D-CPU44SA |
| CS1D-CPU44S | CS1D-CPU44SA |
| CS1D-CPU65S | CS1D-CPU67SA |
| CS1D-CPU67S | CS1D-CPU67SA |
The recommended replacement for an existing CQM PLC is a CJ2M PLC.
There are significant differences between a CQM PLC and a CJ2M PLC. The CJ2M is an upgrade in terms of specifications and features, however there are several points to be aware of when performing a replacement.
- CJ2M PLCs do not have built in I/O points.
- CX-Programmer is required to connect to and program a CJ2M PLC. A programming console cannot be used.
- CJ2M PLCs use different expansion units/modules to those used by a CQM PLC.
The recommended replacement for an existing C__ PLC is a CJ1G or CS1H PLC, or in the specific case of a C200 series PLC, a CS1G PLC may be used instead.
There are significant differences between the C__ PLCs and the CJ1G or CS1H/G replacements.
- All CPU and expansion units require replacement.
- All IO and SIOU units require replacement.
- Specific networking units will be required for any networking functionality.
- If analog signalling is required, the ladder program will require checking and testing to verify their functionality. This is due to the method of handling analog signals changing between the models of PLCs. Program modification will be required.
- If position control is required, rewiring and program modification will be required.
Note that CX-Programmer can be used to convert a C200, C1000 or C2000 program to either CS1 or CJ1 format, however C500 PLCs cannot connect to CX-Programmer. To work around this, Sysmac Support Software or Ladder Support Software can be used to convert a C500 program to a C2000 program, which can then be opened in CX-Programmer and converted to the required PLC model.
C200H to CS1 Replacement Guide
The recommended replacement for an existing CV or CVM PLC is a CS1G or CS1H PLC.
Some CV/CVM units can be used with a CS1 PLC, but not all. It is recommended to read the relevant reference pages to determine which elements of an existing system require replacement.
Most data can be converted from CV/CVM to CS1, but not all. Confirm the operation of the program and data before using the replacement PLC in a production environment.
For all replacement PLCs, OMRON strongly recommends that the replacement is thoroughly tested and verified to function as required before the system is used in a production environment. Errors and faults may occur during conversion processes that can cause the system to act in an unexpected manner.