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Entry type: FAQ, Entry ID: 58496697, Entry date: 04/29/2016

Why is the status value A090 (hex) output for Modbus/TCP although you have entered the correct license?

  • Entry
  • Associated product(s)
Cause and remedy for status value A090 (hex).

There are different reasons why the status value A090 (hex) is output for the mode block although you have entered the correct license.

You have entered the license key only in the Data View of the license data block.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.
You have used the number 0 (zero) instead of the letter O in the REG_KEY.Make sure that the REG_KEY string consists only of letters.
The pointer to the license DB has been forgotten or incorrectly specified.

Make sure that the pointer to the license DB is correctly specified.

You can check this by opening the instance DB of the Modbus block ONLINE. In the Data view you can check the license at the "REG_KEY" parameter.

There are still errors in the initialization of the Modbus block.As long as there is an error in the initialization of the Modbus block and you get 16#A080 (hex) as status, the REG_KEY cannot be evaluated.
You call the Modbus block in OB121.Remove call of the Modbus block from OB121.
You have not inserted the FC10 "EQ_STRNG" function in the project or the FC10 "EQ_STRNG" function has a different FC number.

This affects the following products and versions:

  • S7 OpenMODBUS/TCP (V4.0 and V4.1)
    (V2.0, V2.1, V2.2, V2.3 and V2.4)
  • SIMATIC Modbus/TCP RED V2 (V2.0)

This affects neither the following versions of the products listed above nor these products: SIMATIC Modbus/TCP SENTRON PAC and SIMATIC Modbus/TCP PN CPU Redundant.

Make sure that you have inserted the FC10 "EQ_STRNG" function in your project. These are located 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 FC10 "EQ_STRNG" function with the new FC number in the Modbus blocks.

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