RS485 based 9-bit Network (Multidop Mode)

RS485 based 9 Bit Network

Please bookmark only: rs485.bocc.de

News:

2002/09/28:

My first hardware is ready. A RS232 to RS485 converter:

2002/09/27:

The new software version (coming soon) contains configuration files:

/etc/net9eth.conf

#there are two possibilities:

# filename	ip	hw	io	irq	baud
net10.conf	192.168.010.020	UART16550A	0x3f8	4	38400
# filename	ip	file	line-no	baud
net12.conf	192.168.012.040	/proc/tty/driver/serial	0	38400

and for each net9 device (example: net10.conf):

#there is an entry for each node

node 22		# this is the configuration for the node 022 on network 1
	protocoll 0
	ping ?
endnode

node 24		#this is my first linux test box>
	protocoll 2
	ping ICMP
endnode

2002/09/26:

Erratum: Olof Tangrot found an error in crc.h.

unsigned char UpdCRC8(unsigned char BYTE, unsigned char CRC)
{
return(CRC8_TABLE[BYTE ^ CRC]); <--correct this line
}

and Frieder Ferlemann the missing GND connection in PC-RS485.pdf
for the RS232 connection.

2002/05/30:

I am working to alter a ipv4 udp packet from a normal ethernet interface
to a net9 packet and to convert the answer from a net9 device
to a ipv4 udp packet. If you have suggestions, how to do this,
please email me.

2002/02/15:
RS485 as a Linux ethernet interface: Net9eth-0.0.1.tgz (42kb)
I have rewritten the code. Now it is a ethernet module. Ping works.

2002/01/28:
Linux Driver (Module) available: Net9-0.0.2.tgz (25kb)

2001/12/06:
You need the plugin from Adobe to view the svg graphics.
Linux/Mozilla: www.adobe.com/svg/viewer/install/old.html
Win,Mac: www.adobe.com/svg/viewer/install
I am working on frame types 1,2

2001/12/02:
Linux Driver (Module) available: Net9-0.0.1.tgz (25kb)

This code realises the frame type 0.
Expand the file into a new directory and read the README_Net9 file.
Thanks to Alessandro Rubini / Jonathan Corbet for writing the Book "Linux Device Drivers"

Related Scematic Drawing PC-RS485.PDF (119kb)

My Hardware Setup for Tests

PCB-Boards

(33kb)

Upper pcb board: 89C2015 with a A/D converter
My source of type 0 frames.

Lower pcb board: 89C2015 with a LCD display
Diplays the received frames as hex digits
Scematic Drawing: LCD.PDF (250kb)

Frame of Type 0 on the LCD display

(10kb)

Description of the used Protocol

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