STE 80722 
– 34 – 
Section 5 
 
Simple Protocol Communication 
 
The simple protocol communication issues a command to the robot controller and 
performs start/stop operation of the robot, transfer of program files, and monitoring of 
the status. 
 
5.1  Transmission Protocol 
 
The RS-232C HOST port and Ethernet IP0 port wait for requests from the host 
computer after the power is supplied to the robot controller. 
Basically, the host computer is a master station and the robot controller is a slave 
station.    The robot controller sends back necessary data to the host computer in reply 
to commands reached from the host computer. 
 
 
 
 
 
 
 
 
 
Fig. 5.1    Basic communication 
 
Should the robot controller return an NG (Non-acknowledge) code in response to a 
command from the host computer, or should the robot controller give no response at all, 
resend the command from the host computer.    Even should an error have occurred 
while transmitting a file, resend the file upload (or download) command from the host 
computer. 
 
Furthermore, after receiving text from the controller, insert a delay of about 50 msec 
before beginning to transmit subsequent text from the host computer.