Most current information

You can find the most current information about the Frankfurt RS-232 module at
http://www.grodansparadis.com/frankfurt/rs232/frankfurt-rs232.html. On the site you can also find links to the latest firmware, drivers and schematics etc for its use.

The raw facts

Parameter Value
Current hardware reversion B
Current firmware version 1.0.0
Supply voltage +9-+28 VDC
PCB Size 42mm x 72mm
Power requirements 0.1W
Communication: CAN4VSCP (CAN) 125 kbps
Communication: RS-232 115200 baud N81


Schematics: Rev B


RJ-XX pin-out

The unit is powered over the CAN4VSCP bus. The CAN4VSCP normally uses CAT5 or better twisted pair cable. You can use other cables if you which. The important thing is that the CANH and CANL signals uses a twisted cable. For connectors you can use RJ10, RJ11, RJ12 or the most common RJ45 connectors.

Recommended connector is RJ-45,RJ-12 or RJ-11 with pin out as in this table.

Pin Use RJ-11 RJ-12 RJ-45 Patch Cable wire color T568B
1 +9-28V DC - - RJ-45 Orange/White
2 1 +9-28V DC - RJ-12 RJ-45 Orange
3 2 1 +9-28V DC RJ-11 RJ-12 RJ-45 Green/White
4 3 2 CANH RJ-11 RJ-12 RJ-45 Blue
5 4 3 CANL RJ-11 RJ-12 RJ-45 Blue/White
6 5 4 GND RJ-11 RJ-12 RJ-45 Green
7 6 GND - RJ-12 RJ-45 Brown/White
8 GND - - RJ-45 Brown

RJ-11/12/45 pin-out

RJ-11/12/45 pin-out

:!: Always use a pair of twisted wires for CANH/CANL for best noise immunity. If the EIA/TIA 56B standard is used this condition will be satisfied. This is good as most Ethernet networks already is wired this way.

RS-232 connector pin-out

The RS-232 connectors is not mounted on the TTL versions of this product.

The RS-232 female is numbered like this if you look into it

coupled like this

pin Description
1 unconnected
2 Transmit data from Frankfurt RS-232
3 Receive data to Frankfurt RS-232
4 unconnected
5 Signal ground
6 unconnected
7 RTS (Request to send)
8 CTS (Clear to send)
1 unconnected

:!: RTS/CTS is currently not used.

Connect to host like this

a standard straight RS-232 cable will work fine.

TTL Connector

:!: The TTL connector have use only on the TTL versions of the module.

Pin Description
1 Power from CAN4VSCP bus
2 TTL level RX
3 TTL level TX

PIC programming Connector

pin Description
1 Reset

Functionality of the status LED

The LED is used to indicate a working device. It will light steady when the firmware is running and no faults are detected and it will blink with different frequency when there are bus errors and warnings as of the table below.

LED Description
Steady Powered. No error. Firmware running.
Slow blinking Bus error warning. Something is wrong on the CAN4VSCP bus.
Fast blinking Bus passive. The node will not flag errors on the bus anymore but will still send and receive.
Very fast blinking Bus off. Something is very wrong of the CAN4VSCP bus and the driver to the bus has unconnected itself from the bus. When the bus behaves as normal again it will automatically connect again. The problem can typically be shorted CANH/CANL, only one devices on the bus, a device with wrong bitrate on the bus. To not terminate both ends of the bus with a 120 ohm resistor can also give this problem.


CAN4VSCP is a CAN based bus running at 125 kbps with the addition of DC power. If you are interested in how CAN works you have a pretty good intro here.

CAN is known to be robust and is there for used in vehicles and in the industry.

Paradise of the Frog AB Brattbergavägen 17 820 50 LOS SWEDEN
email: info@grodansparadis.com phone: +46 (0)8 40011835

hardware.txt · Last modified: 2018/02/08 17:29 (external edit)