
Chapter 3 - Operating and Connection Elements, Connection Assignments
11
AMA 310/UMS V21.0
3.3
Back Panel
Figure 3-2 Back panel
3.4
USB-A-Interface
Pin 1 = Vcc (+5 V)
Pin 2 = Data D -
Pin 3 = Data D +
Pin 4 = GND
Figure 3-3 USB-A-interface
According to the specification 1.1 the interface works in full speed with a maximum of 12 MBit/s.
The measuring instrument serves as a master here, i.e. it takes over the full control of the interface.
Before an application can communicate with a USB unit, the host has to know the type of the
device and load an appropriate driver. This happens after a device has been connected to the USB
interface. This process is called enumeration. The standard defines several USB device classes.
However, the measuring instrument only supports the class MASS STORAGE DEVICE (USB
stick).
Via the integrated FAT32 file system the software of the measuring receiver can write files on the
USB stick and read them.
The USB driver has been optimized for the stick provided. This means that this stick should be
used.
If the software tries to access the USB interface without a stick being connected, the LC display
shows the error message "ERROR USB-MassStorage Aborting!"