OEM729 Interface Connectors

P1802 Main Connector 24-Pin Header

Pin

Signal Name

Signal Type

Signal Direction

VIL Max (V)

VIH Min (V)

VOL Max (V)

VOH Min (V)

Drive (mA)

Description

1

GND

PWR

-

-

-

-

-

-

Ground reference

2

USER11

3.3V CMOS

Input/
Output

0.7

2.1

0.4

2.9

4

User GPIO.

Internal 10 kΩ pulldown.

3

VARF

3.3V CMOS

Output

-

-

0.4

2.9

4

Variable Frequency output

Edges can be synchronized to the GNSS time reference.

Internal 10 kΩ pullup

4

PPS

3.3V CMOS

Output

-

-

0.4

2.4

16

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.

5

3V3

PWR

-

-

-

-

-

-

3.3 V ±5% supply input

6

3V3

PWR

-

-

-

-

-

-

3.3 V ±5% supply input

7

COM3_RX/
EVENT22

3.3V CMOS

Input

0.7

2.1

-

-

-

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.

8

EVENT1

3.3V CMOS

Input

0.7

2.1

-

-

-

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.

9

ERROR

3.3V CMOS

Output

-

-

0.4

2.9

4

ERROR output

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

Internal 10 kΩ pulldown.

10

PV

3.3V CMOS

Output

-

-

0.4

2.9

4

Position Valid output

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

Internal 10 kΩ pulldown.

11

COM2_CTS

3.3V CMOS

Input

0.7

2.1

-

-

-

COM2 Clear To Send input

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

Internal weak (40 kΩ to 100 kΩ) pullup.

12

nRESET_IN

Other

Input

0.8

2.3

-

-

-

Active Low.

Resets the OEM729 receiver card. This pin must be held low for a minimum of 100 microseconds to guarantee operation.

Internal 10 kΩ pullup.

13

COM2_RTS

3.3V CMOS

Output

-

-

0.4

2.9

4

COM2 Request To Send output

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

For SPAN applications, this pin can be configured to output a timing signal periodically (generally 1PPS).

14

COM2_RX

3.3V CMOS

Input

0.7

2.1

-

-

-

COM2 Receive Data input

Internal weak (40 kΩ to 100 kΩ) pullup.

15

COM1_CTS/
COM1_RXD-

COM1_CTS: RS-232

Input

-

-

-

-

-

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)

COM1_RXD-: RS-422

Input

-

-

-

-

-

16

COM2_TX

3.3V CMOS

Output

-

-

0.4

2.9

4

COM2 Transmit Data output

For SPAN applications, this pin can be configured to output a timing signal periodically (generally 1PPS).

17

COM1_RTS/ COM1_TXD-

COM1_RTS:
RS-232

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)

COM1_TXD-:
RS-422

Output

-

-

-

-

-

18

COM1_RX/
COM1_RXD+

COM1_RX:
RS-232

Input

0.7

2.1

-

-

-

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).

COM1_RXD+:
RS-422

Input

-

-

-

-

-

19

COM3_TX/USER0

3.3V CMOS

COM3_TX:
Output

-

-

0.4

2.9

4

This pin is internally multiplexed. COM3_TX is the default.

COM3_TX: COM3 Transmit Data output.

USER0: User GPIO. Internal 10 kΩ pulldown.

USER0:
Input

0.7

2.1

-

-

-

20

COM1_TX/
COM1_TXD+

COM1_TX:
RS-232

Output

-

-

-

-

-

This pin is internally multiplexed. COM1_TX is the default.

COM1_TX: COM1 Transmit Data output. (±25V tolerant)
For SPAN applications, this pin can be configured to output a timing signal periodically (generally 1PPS).

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

COM1_TXD+:
RS-422

Output

-

-

-

-

-

21

USB_D-

Analog

Input/
Output

-

-

-

-

-

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.

22

USB_D+

Analog

Input/
Output

-

-

-

-

-

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.

23

GND

PWR

-

-

-

-

-

-

Ground reference

24

GND

PWR

-

-

-

-

-

-

Ground reference

P1803 Expansion Connector 16-Pin Header

Pin

Signal Name

Signal Type

Signal Direction

VIL Max (V)

VIH Min (V)

VOL Max (V)

VOH Min (V)

Drive (mA)

Description

1

ETH_RD-

Analog

Input

-

-

-

-

-

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

2

ETH_RD+

Analog

Input

-

-

-

-

-

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

3

ETH_BIAS

PWR

-

-

-

-

-

-

Center tap power for Ethernet magnetics.

4

ETH_TD+

Analog

Output

-

-

-

-

-

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

5

ETH_TD-

Analog

Output

-

-

-

-

-

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

6

ETH_BIAS

PWR

-

-

-

-

-

-

Center tap power for Ethernet magnetics.

7

LED_A

3.3V CMOS

Output

-

-

0.4

2.9

8

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.

8

LED_B

3.3V CMOS

Output

-

-

0.4

2.9

8

Speed indicator
Low = 100 Mbps
High = 10 Mbps

9

GND

PWR

-

-

-

-

-

-

Ground reference

10

CAN1TX

3.3V CMOS

Output

-

-

-

-

-

CAN1 Transmit data

11

CAN1RX

3.3V CMOS

Input

-

-

-

-

-

CAN1 Receive data

12

CAN2TX

3.3V CMOS

Output

-

-

-

-

-

CAN2 Transmit data

13

CAN2RX

3.3V CMOS

Input

-

-

-

-

-

CAN2 Receive data

14

UID

3.3V CMOS

Input

-

-

-

-

-

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

15

VBUS

PWR

-

-

-

-

-

-

5V output for hosted USB devices

16

GND

PWR

-

-

-

-

-

-

Ground reference

 

OM-20000167 v14

November 2019

Email comments to NovAtel_TPUBS@NovAtel.com

7.07.03 / OM7MR0703RN0000
PP7 07.07.04 / EP7PR0704RN0000
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