RS232 Specifications

The RS232 port on the Roboteq controller is configured as: 9600/1/1/EVEN/NO control flow.
Your program needs to configure the port on the computer with these parameters.
I have programmed in Visual Basic in which case you send the commands like: "?A" or "^00 00" defined as strings. you send complete string as it appears enclosed in the double quotes, including the ? or ! or ^.
Example (assume you have a sub named SEND(string) that sends a string via the RS232):

Dim mystring as string
mystring = "?A"
Call Send(mystring)

Private sub Send(anystring as string)
your code specific to the RS232 send function here
end sub

I have not translated this in C but it should work the same way.
Under Windows the transmission time through the RS232 is about one millisec. The controller keeps the commands in a buffer sampled every 16 millisec so the response time to a command is 16 millisec worst case., which more or less should also be the rate at which commands are sent (the buffer accomodates for time variations)

You understood correctly. You need to send the string equivalent of an hex number rather than the hex number as unsigned char.
So for 255 dec you would send "FF" not FF.
Tks
Tony

I forgot to say that we at Roboteq have source code available demonstrating the API interface. It is in VB6.0 but can be easily changed in C. In case you want it, e-mail me at <A href="This email address is being protected from spambots. You need JavaScript enabled to view it." target=_blank>This email address is being protected from spambots. You need JavaScript enabled to view it.
Tks
Tony