OEM729 Interface Connectors

Ground reference

User GPIO.

Internal 10 kΩ pulldown.

Variable Frequency output

Edges can be synchronized to the GNSS time reference.

Internal 10 kΩ pullup

Pulse Per Second output

This signal defaults to one pulse per second but may be altered across a wide range of frequencies using software commands. Edges can be synchronized to GNSS time reference.

3.3 V ±5% supply input

3.3 V ±5% supply input

This pin is internally multiplexed.

COM3_RX: COM3 receive data input.

EVENT2 input. Rising or falling edge triggered. This is used to provide position or time data on an external trigger.

Internal 10 kΩ pullup.

EVENT1 input

Rising or falling edge triggered. This input is used to provide a position or time data log based on an external trigger.

Internal 10 kΩ pullup.

ERROR output

Normally low. A high output on this pin indicates that the receiver is in an error state.

Internal 10 kΩ pulldown.

Position Valid output

A high output on this pin indicates that the receiver has computed a valid GNSS position.

Internal 10 kΩ pulldown.

COM2 Clear To Send input

This is an optional flow control signal for the COM2 UART.

Internal weak (40 kΩ to 100 kΩ) pullup.

Active Low.

Resets the OEM729 receiver card. This pin must be held low for >20 µs while stable power is already applied, to reset the OEM729 card.

It is recommended to hold the nRESET_IN pin low for a >150 ms when initially applying power to the card, giving the power supply time to stabilize before the card starts to boot.

Internal 10 kΩ pullup.

COM2 Request To Send output

This is an optional flow control signal for the COM2 UART.

COM2 Receive Data input

Internal weak (40 kΩ to 100 kΩ) pullup.

This pin is internally multiplexed. COM1_CTS is the default.

COM1_CTS: COM1 Clear To Send input. This is an optional flow control signal for the COM1 UART (±25V tolerant).

COM1_RXD-: This is one half of the COM1 RS-422 receive differential pair (2V differential typical)

COM2 Transmit Data output

This pin is internally multiplexed. COM1_RTS is the default.

COM1_RTS: COM1 Request To Send output. This is an optional flow control signal for the COM1 UART (±25V tolerant).

COM1_TXD-: This is one half of the COM1 RS-422 transmit differential pair. (2V differential typical)

This pin is internally multiplexed. COM1_RX is the default.

COM1_RX: COM1 Receive Data input (±25V tolerant).

COM1_RXD+: This is one half of the COM1 RS-422 receive differential pair (2V differential typical).

This pin is internally multiplexed. COM3_TX is the default.

COM3_TX: COM3 Transmit Data output.

USER0: User GPIO. Internal 10 kΩ pulldown.

This pin is internally multiplexed. COM1_TX is the default.

COM1_TX: COM1 Transmit Data output. (±25V tolerant)

COM1_TXD+: This is one half of the COM1 RS-422 transmit differential pair (2V differential typical)

USB device signal.

This is one half of the USB differential pair. USB_D+ and USB_D- must be length-matched and routed as a 90 Ω differential pair.

USB device signal.

This is one half of the USB differential pair. USB_D+ and USB_D- must be length-matched and routed as a 90 Ω differential pair.

Ground reference

This is one half of the Ethernet receive differential pair (100 Ω pair).

This is one half of the Ethernet receive differential pair (100 Ω pair).

Center tap power for Ethernet magnetics.

This is one half of the Ethernet transmit differential pair (100 Ω pair).

This is one half of the Ethernet transmit differential pair (100 Ω pair).

Center tap power for Ethernet magnetics.

Activity/Link indicator output.

Polarity of the indicator signal is low. When there is an active link, the pin is low. When there is activity on the link, the pin outputs a blink signal.

Speed indicator
Low = 100 Mbps
High = 10 Mbps

Ground reference

CAN1 Transmit data

CAN1 Receive data

CAN2 Transmit data

CAN2 Receive data

USB Port Mode

Leave this pin floating to ensure the USB port is in Device mode.

Host mode is not currently supported on the OEM729.

Internal 10 kΩ pull up

5V output for hosted USB devices