Description
Below are the reasons why the status value A090 (hex) is output for Modbus TCP although you have entered the correct license.

• You have not inserted the FC10 "EQ_STRNG" function in the project or the "EQ_STRNG" function has a different FC number.
• You have entered the license key only in the Data View of the license data block.

Proceed as below to clear the reasons for output of the status value A090 (hex).

• Make sure that you have inserted the FC10 "EQ_STRNG" function in your project. This is available in the Standard Library of STEP 7 under IEC Function Blocks -> Blocks. If the FC number is already being used in the user program, you must re-wire the "EQ_STRNG" function with the new FC number in the Modbus blocks.
• If the license key is entered in the Data View of the license data block, this is overwritten with the initial value when the CPU is restarted. Therefore, you must enter the license key as the initial value in the Declaration View. Then the license key can be initialized in the Data View.