Need VB source code for Modbus with RS 232 / RS 485...

Halo...
I need source code example programming and implementing modbus protocol with RS 232/485 PC Comm port using Visual Basic for communication with barcode scanner (CPT 8000). Would you give me information abou it?
regards

Yenkbz
 
I have been looking for example VB source code for ModBus RS-232/485 devices. If you could please share with me I would appreciate it. I am not skilled in VB and have a project comming up and would like to get a jump on things.

Ty
[email protected]
 
i need now serial communication program in vb
can u send witth in 2days.my mail id is
yuv_n17 @rediffmail.com
 
Hi Grant

I'm doing this small application using mscomm control
i have a number of devices connected to the serial port (rs-232). this port has a rs-232 to rs-485 converter. the rs-485 converter has the abovesaid devices connected serially. now i want to keep checking the status (polling) of each of the device. how can i achieve it using the mscomm control by not keeping the computer busy? the devices used r slave devices. i keep on sending them query and waiting for the response. how can i code it in VB??

hope u can help
Samir
 
Just get a FESTO PLC FEC34, connect those device through rs485 to com port of FEC34 now, you can can those device reading on any DDE application such as Excel. no need to write code

Good luck!
Wayne
 
u should use Rx (pin 2), Tx(Pin3), Gnd(Pin5) and DTE(pin4). DTE is used for select rs 485 mode (receive or transmit) half duplex, but if u r using full duplex, u shouldn't use DTE in DB9 (serial connection).

first u should convert rs 232 to rs 485, u can use max232 or icl232 for rs232 to TTL, and 75176 for rs 485 halfduplex and 75178 for full duplex

herry
 
sir

we need a source code for rs485 serial port communication to interact the pc with the number of AVR processors. could u help me out plz?
thanx.
 
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