English => Interfaces, Pinouts, Cables => Topic started by: edsancar on Aug 04, 2006, 01:41

Title: USB-RJ45
Post by: edsancar on Aug 04, 2006, 01:41
I have an Egan Teamboard (Electronic Board) which I inherited in my office.  From the information I have gathered (manuals and connection guides) the comunication to this device is via USB.
The complication is that the entrance to the Teamboard is a RJ-45 connector.  In the installation guide they show and Adapter but when I called the supplier, its representaive in Mexico, told me that I can constuct my own cable using a USB connector and a RJ45 with direct pin assignment.
The complication comes when USB used 4 pins and RJ-45 uses 8, Also when I've seen pinouts for RJ-45 I have nevers seen power lines (+vdc, 0Vdc)
Has anyone worked this out previously?
Thanks in advance for your support.
Title: USB-RJ45
Post by: abhishek on Aug 04, 2006, 15:01
I dont think direct pin assignment is possible.
A controller is required in beetween.
But heres a hint:
USB had D+ and D- signals.
These can be used as TX+ and RX+.
GND can be used as TX- and RX- (common).
A typical Ethernet cross cable pinout:

Name             NIC1    Color        NIC2            Name
TX+ (BI_DA+)    1 White/Orange   3       RX+ (BI_DB+)
TX- (BI_DA-)      2 Orange            6       RX- (BI_DB-)
RX+ (BI_DB+)    3 White/Green    1       TX+ (BI_DA+)
- (BI_DC+)         4 Blue               7        - (BI_DD+)
- (BI_DC-)          5 White/Blue      8        - (BI_DD-)
RX- (BI_DB-)      6 Green             2        TX- (BI_DA-)
- (BI_DD+)         7 White/Brown   4        - (BI_DC+)
- (BI_DD-)          8 Brown            5        - (BI_DC-)

PS: It might damage the hardware so be careful.
Title: USB-RJ45
Post by: abhishek on Aug 04, 2006, 15:06
Try experimenting with D+ and D- with TX+ and RX+ (cant say which one is which)
And by the way only 1 pair of TX and RX is used in RJ45 (4 wires). The rest 4pins are not used.
Title: USB-RJ45
Post by: on Aug 04, 2006, 17:35
With regard to MAX 232 IC. What's the function.
Title: USB-RJ45
Post by: Knucklehead on Sep 29, 2006, 20:59
Just because a device uses an RJ-45 connector, doesn't mean it's meant for Ethernet. RJ-45 connectors are also used quite frequently for certain serial devices; notably, signboards and other devices which need to be controlled from large distances. Such devices typically fall under the RS-485 heading, which unfortunately has no standard pinout.

Your best bet is to look in the manual for the board for the appropriate pinout.
Title: USB-RJ45
Post by: edsancar on Oct 03, 2006, 19:23
Ok, thanks for your comments, looks like I need an interphase and the equipment supplier has to provide it.