Page 134 - Welding Robots Technology, System Issues, and Applications

Robotic Welding: System Issues 121

file is compiled by the rpcgen tool, generating the basic calls and data structure
prototypes necessary to invoke the RPC services available from the robot
controller. The necessary code was added to each basic function and packed into an
ActiveX software component named PCROBNET2003 [39]-[41]. The complete set
of functions included in this object is listed in Table 4.1.

It should be noted that, although this software component was built using the
DCOM/OLE/ActiveX object model, it does not run the Microsoft RPC
implementation but instead the already mentioned SUN RPC 4.0 port to the Win32
API.

Table 4.1. Methods and properties of the software component PCROB NET2003 [40],[41]

Function Brief description
open Opens a communication line with a robot (RPC client)
close Closes a communication line.
motor_on Go to run state
motor_off Go to standby state
prog_stop Stop running program
prog_run Start loaded program
prog_load Load named program
prog_del Delete loaded program
prog_set_mode Set program mode
prog_get_mode Read actual program mode
prog_prep Prepare program to run (program counter to begin)
pgmstate Get program controller state
ctlstate Get controller state
oprstate Get operational state
sysstate Get system state
ctlvers Get controller version
ctlid Get controller ID
robpos Get current robot position
read_xxxx Read variable of type xxxx (there are calls for each type of variable
defined in RAPID [43])
read_xdata Read user defined variables
write_xxx Write variable of type xxxx (there are calls for each type of variable
defined in RAPID [43])
write_xdata Write user defined variables
digin Read digital input
digout Set digital output
anain Read analog input
anaout Set analog output

To use a remote service the computer running the client application needs to make
properly parameterized calls to the server computer, and receive the execution
result. Two types of services may be considered: synchronous and asynchronous.
The synchronous services return the execution result as the answer to the call.