loadtestrunner.sh command line options

Quick question:

I know that on the command line, the -m option sets the limit value for the specified load test.
But the units for this seem to be the number of seconds the test will run.

Is there a way to specify the number of times the test will run? Instead of 3600 seconds, I need the test
to run a total of 3000 times. That's a little different.

Also, what are the allowed values for the -R option?