Modbus RTU program

[anjali]

Hello..


I am doing project on modbus using pic c compiler, but am getting error for the inbuilt functions like:use parameter value is out of range "error" , undefinied identifier kbhit ...

But if i remove the error in the given statement below the complier is not giving any error.. I want to know what is the function of the "error" here..
Is it ok if i dont use "error"?

#use rs232(baud=MODBUS_SERIAL_BAUD, UART1, parity=N, stream=MODBUS_SERIAL,error)

looking forward to the reply....

[jeremiah]

you didn't spell it correctly. It is "errors"...notice the "s".

The purpose of it is to keep your hardware from locking up. Leaving it out will cause your UART to lockup eventually.

[anjali]

Oh okay... is it an that essential? because am using modbus poll to check the transfering of data, but when i click the connect option of modbus poll software its giving timeout error... why do time out error occurs? is including "errors" must??

waiting for the reply...!

[jeremiah]

I know little of modbus. ERRORS is a general UART option, not specific to modbus. If the UART encounters a particular hardware error, it will stop receiving if I understand it correctly. Using ERRORS makes the compiler add code that clears those hardware errors and allows the UART to work correctly again. Leaving it out means that if those errors occur your UART connection will no longer function correctly.

[FvM]

Yes, you absolutely should use errors. But there may be other problems in your MODBUS application in addition.

[temtronic]

You might be getting the 'timeout' error due to the UART being 'locked up' or 'jammed' since you don't have the 'errors' option.
I'm not a MODBUS guy but do know you must have 'errors' in the uses rs232(....) line.

[anjali]

Thanks a lot for both...!!!! it worked correctly : :)
as you said it was just a mistake of "s"...


Thanks once again:)