The invention relates to a field device for automation systems, comprising a unit for internal data organisation, means for recording process parameters and/or means for outputting regulation parameters, means for processing signals according to the recorded regulation parameters or the regulation parameters to be output, and at least one communication interface. The means and the communication interface thus communicate with a unit for internal data organisation in order to exchange data between each other. A transaction manager unit, which is provided to control blockings, transactions and/or users, is used to control the access via the means and via the at least one communication interface to the data of the unit for internal data organisation between the means, the at least one communication interface and the unit for internal data communication.