Delta RMC151 - Manual (Page 510)

RMC70/150 and RMCTools User Manual
3. Bruce edits the Program Triggers to start the Cycle program when
StartProgram is 1, and to start the MoveHome program when
StartProgram is 2.
4. Now Bruce is ready to perform the communications. To run the Cycle program,
the PLC first sets up the position and speed variables, then sets the
StartProgram variable to 1. To run the program again, the PLC must first set
the StartProgram variable to some other number (such as 0), then set it to 1.
To run the MoveHome program, the PLC must first set the HomePosition
variable, then set the StartProgram variable to 2.
Handshaking
The I/O Modes do not require any handshaking, but you may wish to make some simple
handshaking so the PLC knows the RMC is running normally and is performing the
requested actions. Here are some methods of doing simple handshaking:
• Put the StartProgram Variable in the Indirect Data Map
In the example above, the StartProgram variable could be put in the Indirect Data
Map, so the PLC could see that it changed correctly and knows the communications is
working properly.
• Use the Task Status Registers.
The Task status registers indicate whether a task is running, and which user program
it is running. You can add these registers to the Indirect Data Map so the PLC can see
if the correct user program is running.
• Create a Program Done Variable
You can create a variable for reporting when a user program is complete. For example,
at the beginning of the user program, add a step with an Expression (113) command
that sets the variable to zero. Then, at the end of the user program, add a step with
an Expression (113) command that sets the variable to a certain number indicating
that the user program is complete. Make sure to include this variable in the Indirect
Data Map so the PLC can see it.
490 Delta Computer Systems, Inc.