Rockford Systems, LLC
1-800-922-7533 (U.S.A. only)
17
SECTION 5—PROGRAMMING
Stop-Time Measurement Device
(Continued on next page.)
The object of the STM device is to check the stopping
time of a machine. This time is then used in a safety
distance formula to determine the proper safety distance
of safeguarding devices from the point-of-operation
hazard. The two most common safeguarding devices that
require this are two-hand controls and presence sensing
devices. On most machines where the STM device will be
used, there will be a down movement of the ram,slide, or
platen on a mechanical or hydraulic power press or press
brake. On mechanical power presses, OSHA requires that
the stop signal be given at the 90°position of crankshaft
rotation (at the halfway point in the downstroke). ANSI
requires the use of the highest velocity in the hazardous
portion of the stroke. See details of the OSHA and ANSI
formulas on pages 6 - 8 of this manual.
In the
MM PARAMETER 3 MEASURING
programming
menu, submenu
P3 SPM METHOD
there are three
choices:
TEACH-IN
(factory setting) - With the cable and
magnet attached to the slide, inch the machine to the
start point of measurement(using the OSHA formula,
this is at 90°position of crankshaft rotation or at
the halfway point in the downstroke on mechanical
power presses). Next, enter this point to give the stop
signal. (Refer to the
MM STOP-TIME
MEASURING
section on page 20 for details.)
MANUAL
- The start point of the measurement can
be set manually. This is done in the MM
STOP-TIME
MEASURING
program using the
▲
or
▼
buttons
and scrolling to the position where the sensor is to
provide a stop signal to the meter.
TEST STROKE
- Cycle the machine with the cable
and magnet attached to the ram. The meter will
automatically decide where the highest velocity is
in the cycle and provide the stop signal accordingly.
This should only be used on machines with eccentric
drives, no ton machines with constant velocity.
Note: Regardless of which method of testing is selected, if
the machine that is being tested has a crankshaft, and if
the crankshaft rotates beyond BDC (bottom dead center),
the readings will not be accurate. If the stopping point is at
90°, move the stopping point higher in the stroke so that
the machine stops before BDC.
ON/OFF
To turn the meter
ON
, press the
▲
button and
ENTER
button at the same time. The display wills how
STOP-
TIME METER
DELTA T V2.07. Press any button and
then use the
▲
or
▼
buttons to scroll through for menu
selections.
To turn the device
OFF
,scroll to the
MM POWER DOWN
SWITCH OFF
. Press
ENTER. POWER OFF
. . . is displayed
and the device shuts off. The STM device will automatically
shut down after 10 minutes if it is not being used
Figure 5.1 - Crankshaft Rotation
Figure 5.2 - Mechanical Power Press
