Differences in modicon modbus drivers and winlinx driver


Thread Starter

yogesh butala

Dear Sir,

here i am sending response after min 15msec after receipt of valid query.

I would like to have your comment regarding my
following observation:

I have implemented MODBUS RTU protocol.
baud rate 9600
parity none
stop bit 1
word length 8 bits
CPU used in energy meters is 8051.

Data type is IEEE floating point format.

Suppose i send a request to slave for say
5 floating point parameters then the query sent by master should be as follows:

0x01 ,0x03,0x00,0x00,0x0A,XX,XX (XX = CRC)

stn No Func code Start Add Length of data CRC

The above query is as per Modicon Modbus
My meter is responding well for above query.

But if i request same number of parameters
through RSVIEW then the query sent by Master
is different i.e only 5 registers.

data length (no of registers requested )

i would like to have your comment on length
of holding registers and size of holding reg
(i.e. whether the holding register will be 16
bit or 8 bit)