USB Ports
OEM7 receivers have USB 2.0 compatible ports. The number of ports, bit rate and modes available vary depending on the receiver.
|
Receiver |
Number of Ports |
Port Bit Rate |
Mode |
USB Signals |
|---|---|---|---|---|
|
OEM719 |
1 |
12 Mbps |
Device only |
Pin 3 D(-) and Pin 4 D(+) on P1701 (main header). |
|
OEM729 |
1 |
12 Mbps |
Device only |
Pin 21 D(-) and Pin 22 D(+) of P1802 (24-pin header) |
|
OEM7600 |
2 |
480 Mbps |
1 Device and 1 Host |
USB0: Pin 48 D(+) and Pin 50 D(-) on P1701 USB1: Pin 47 D(-) and Pin 49 D(+) on P1701 |
|
OEM7700 |
2 |
480 Mbps |
1 Device and 1 Host |
USB0: Pin 48 D(+) and Pin 50 D(-) on P2001 USB1: Pin 47 D(-) and Pin 49 D(+) on P2001 |
|
OEM7720 |
2 |
480 Mbps |
1 Device and 1 Host |
USB0: Pin 48 D(+) and Pin 50 D(-) on P1901 USB1: Pin 47 D(-) and Pin 49 D(+) on P1901 |
See OEM719 Technical Specifications, OEM729 Technical Specifications, OEM7600 Technical Specifications, OEM7700 Technical Specifications and OEM7720 Technical Specifications for further information on USB specifications and pin assignments.
If the USB port is being routed to a external device, ESD protection is needed. For an example of a USB interface circuit, see USB Interface.
USB Modes
The USB mode of a port (Device or Host) is set by the state of the UID pin. See OEM7600 Interface Connector, OEM7700 Interface Connector and OEM7720 Interface Connector for more information.
When a USB port is set to Device mode, it is used to communicate between components in the GNSS system and to external data communications equipment such as computers and data loggers.
When the USB port is set to Host mode, it supports USB mass storage devices, such USB memory sticks.
For information about the USB memory sticks supported by OEM7 receivers, see USB Devices Supported.
Multiple USB Ports
OEM7 receivers with a 60 pin interface connector (such as the OEM7700) have two USB ports, one configured as a device and one configured as a host.
The state of the USB Port Mode Select pin (pin 51) determines which USB port is configured as host.
|
USB Port Mode |
USB0 Mode |
USB1 Mode |
|---|---|---|
|
Tied Low |
Host |
Device |
|
Tied High Left Unconnected |
Device |
Host |
USB0 is the recommended interface if only one of the USB ports is used, as USB0 provides a connection for VBUS.
USB OTG is not supported. The state of the USB Port Mode Select pin is sampled when the receiver starts and the USB mode of both ports is set at that time.