Here are the steps to enable a third Serial port and CAN connectivity bus interface on OEMV1 and OEMV2.
1. COM3 OEMV1: Event 1 must be disabled using the MARKCONTROL command when LVTTL is in use.
Pin 4: LVTTL_Tx.
pin 9: LVTTL_Rx Event 1(pin 9) and USB D+ (pin 4) are not available when LVTTL is in use.
OEMV2: Event 2 must be disabled using the MARKCONTROL command when LVTTL is in use.
Pin 7: LVTTL_RX
Pin 19: LVTTL_Tx GPIO_USER0 (pin 19) and Event 2 (pin 7) are not available when LVTTL or CAN bus are in use. ** COM3 will be enabled in FW 3.200.
2. CAN BUS OEMV1:
CAN1 is not multiplexed and is enabled by default. CAN2 on CAN BUS is enabled with the following commands:
MARKCONTROL MARK2 DISABLE
Pin 6: Rx = 0 = R Pin 7: Tx =1 = D OEMV1 CAN 1 shares Event2 and VARF - these are therefore not available when the CAN 1 in use. OEMV2 (CAN1): Pin 7: Rx = 0 = R
Pin 19: Tx =1 = D OEMV2 CAN1 shares with COM3 / Event 2 and a User GPIO - these are not available when using CAN
For the OEMV1/2 at the point on the interface they are implemented to there is a Rx and TX line. Texas instruments 65HVD231 is a suitable driver to the signal available http://focus-webapps.ti.com/general/docs/sitesearch/searchdevice.tsp?partNumber=65HVd231 ** Please note that CAN bus access requires NovAtel API.