PHD User Guide
23
The following shows a typical CAN connection using the SAE J1939 standard:
120 ohm
Terminator
120 ohm
Terminator
Node
Node
Node
Node
Node
T connectors
Variable length
CAN stub (<1m)
CAN Network Backbone
(less than 40 meters long)
Figure 6.2. J1939 CAN connection
6.2. USB
The PHD family supports one USB port capable of full speed USB 2.0. The USB port is configured as Host
or Device based on settings in software. The USB port allows you to connect temporarily to the unit for
the purpose of updating code or configuring the unit.
The following table provides specifications for the USB port:
USB Device Specifications
Item
Min
Nom
Max
Unit
Communication speed - Full Speed
12
Mbps
Capacitance of I/O to ground
2.5
3.5
pF
Reverse standoff voltage (note 1)
5
V
Not 1e:
USB connectors are not rated to survive a short to vehicle battery.
To load the application file:
1. Make sure the PHD is powered off and the USB cable is unplugged.
2. Power Up the PHD
3. Connect the USB cable.
4. Send the application file.
5. PHD should reboot in about 20-30 seconds after the file is sent.