“the H@rt BluePack” is a versatile interface that supports wireless (Bluetooth) and wired (USB) access to a HART network. It can be employed as an up-to-date replacement for the still widely used RS-232HART modem solutions. Additionally, to its modem capabilities, the H@rt BluePack runs an embedded HART master stack. The active HART master stack guarantees compliance with the HART timing requirements regardless of the speed of the PC host application or the data transmission quality between the host and the Bluetooth device. This can be of considerable advantage if using the interface in multi-master environments or in connection with burst-mode slaves. The stack can be configured to work as a primary or secondary master. The interface can be powered via a USB connection or three replaceable AAA cells. Operating in battery mode can be powered down by an on/off button. To increase the battery life span, the device switches to sleep mode if no Bluetooth communication takes place. The activity on the HART network is indicated by one LED.