I am using an RCM4100 or RCM4200 processor. For port D, for example, I know I must define the DINBUFSIZE AND DOUTBUFSIZE parameters, to say, 63 bytes. That works fine if I am using defines to alter the way the program compiles, but how do I dynamically change those values based on a DIP switch setting of my communications protocol? For example, what if I want 255 bytes for Modbus or 511 bytes for DF1 as set by a DIP switch input? Can I use malloc to change these and if so how?