There is one positioning module in market with function similar to TCS/ICS (from Trimble). The manufacturer is called Stahltronic. This product can be operating in half duplex protocol through RS232 port with 7 bytes command sent from master and 14 bytes status echo back from slave. As basic module function calls CALL 22 and CALL 23 are used to establish such protocol with word base (i.e one word = 2 bytes), I am not sure how odd byte can be sent out via RS232 communication port. If possible, which instructions and/or functional calls can be used to handle such protocol?