PLC Type Selection

To access the PLC Type dialog box, select the PLC > Type menu command.

By making a PLC type selection, you enable STEP 7-Micro/WIN 32 to perform instruction and parameter checking, which helps prevent errors as you create your program. Also, after you specify a PLC type for your project, the Instruction Tree shows any instructions that are not valid for your PLC with a red x:

If you open a new project and begin editing a program without making a PLC Type selection, STEP 7-Micro/WIN 32 editors and compilers let you program instructions, addresses, and PLC features that are not supported in all S7-200 PLC models. If you use instructions, addresses, or PLC features in your project that are not supported by your target PLC, when you try to download the project, it will be rejected by the PLC.

This topic discusses the following subjects:

Specifying a PLC Type Selection

Letting STEP 7-Micro/WIN 32 Read the Remote PLC Type

Type Mismatches

Specifying a PLC Type Selection

Back to Top

You can select a PLC by picking a model from the listbox in the PLC Type dialog box. For example, if you have a PLC 214, the listbox displays:

When you make this selection, the range and feature restrictions for the latest firmware release of the PLC 214 are applied. However, you may have an early PLC 214 firmware release that does not support features available in the latest PLC 214 firmware release. To ensure that both your PLC model and your firmware release are taken into consideration when range-checking is performed, you can have STEP 7-Micro/WIN 32 read the information directly from the PLC.

Note:

You do not need to configure communications when you are specifying the PLC type selection; you only need to have communications established if you want STEP 7-Micro/WIN 32 to read the remote PLC type for you.

Letting STEP 7-Micro/WIN 32 Read the Remote PLC Type

Back to Top

To have STEP 7-Micro/WIN 32 read the PLC model and firmware release, click on the button in the PLC Type dialog box.

Note:

You must already have established communications successfully in order to read the PLC model and firmware information. You can use the button in the PLC Type dialog box either to establish communication with a PLC, or to select a target PLC when you have more than one PLC connected to a communication network.

The model and firmware release are displayed as the type selection.

Type Mismatches

Back to Top

If you attempt to download your program to the PLC and the PLC does not match the PLC type selection for your project, an error message appears. Your options depend on what kind of mismatch you have:

Project

Selection

Actual

PLC Type

Your options

CPU 21x type CPU 21x type Since both PLCs are of the same generation,
CPU 22x type CPU 22x type you can either download without correcting the PLC type selection,
    or click on "Set Type to Remote PLC" to correct the selection.
CPU 21x type CPU 22x type You can either download without correcting the PLC type selection,
    or click on "Set Type to Remote PLC" to correct the selection.
CPU 22x type CPU 21x type You must either cancel the download,
    or click on "Set Type to Remote PLC" to correct the selection.

See Also:

Communications

Compiler

PLC Memory Address Ranges

Instruction Support for S7-200 CPUs

Interrupt Event Priority Table