Communicating using 2 MAX485

good morning everyonei am making a project in which there will be a large distance betwwen two aruino's 

one of them will be a joystick which will take the orders and send them to the other arduino 

this is an tutorial for it with arduino

http://pskillenrules.blogspot.com/2009/08/arduino-and-rs485.html

and this is an a example code between two arduinos 

http://arduino-info.wikispaces.com/SoftwareSerialRS485Example

i have a question about this code... i can only send one byte between each on and off operation? (transmitting enable and disable?)or i can send a whole byte?!

wiring between two arduinos 

arduinors485_steckplatine_med_hr.jpg

should there be a delay between each operation? 

this is its pdf

http://www.ram-e-shop.com/ds/ic/MAX485.pdf

thanks in advance!

 

How long are you talking
How long are you talking about here?

**20-25 meters **

20-25 meters