Siemens 1500 datatype wstring

Hi @NB_13466175 ,

The Siemens WString (wide string) type isn’t natively supported as a direct data type in Kepware’s Siemens Plus Suite driver. Kepware can read or write standard STRING types, but WString uses UTF-16 encoding (2 bytes per character), which makes it appear as a byte or hex array to Kepware.

Here’s how you can handle it:

1. Reading the WString:

   • Define the tag in Kepware as Byte Array (for example: DB1101.ByteArray0034.24).

   • This will return the raw 24 bytes (UTF-16 encoded). You can then decode them on the client side as UTF-16 text.

2. Writing to the WString:

   • Kepware can’t write UTF-16 directly through the standard STRING tag.

   • Instead, convert your intended text to UTF-16 bytes and write those as a Byte Array (or HEXSTRING) from your OPC client or script.

   • Example: Writing “HELLO” → 480045004C004C004F00 (UTF-16 LE) to the same address range.

3. Alternative Option:

   • If you have control over the interface on the receiving side, the simplest path is to create a shadow STRING tag in the PLC and mirror it to the WString using PLC logic (STRING_TO_WSTRING or WSTRING_TO_STRING).

   • This allows Kepware to interact normally with the STRING while the PLC handles conversion internally.

Kepware’s Siemens Plus Suite doesn’t yet expose WString as a standalone data type, so handling it as a byte array and decoding externally is currently the most reliable approach.

Thanks,