Stop time measuring systems
Description
The NMG is designed to measure stop times, stop distances and speeds of machines such as presses, large shears, welders, riveting machines and robots. In accordance with national and international safety standards, machinery with dangerous movements must be equipped with protective devices. Improper installation of the safety device (two-hand switch, light curtain, etc.) poses a potential danger to the operator. With NMG2, all important measurement results such as stop time, distance and speed are provided to calculate the minimum safety distance. The safety distance is defined in national and international standards such as EN999 / EN574. To ensure maximum safety, periodic (every 6 months) measurements of stop times must be performed.
The measuring cable of the WS position sensor is connected to the moving part of the machine with a magnetic clip or screw. The sensor sends a digital pulse signal to a counter that is microprocessor controlled. The stop position can be determined with a digital encoder. The operator will set the measuring stop position to the position of the maximum speed of the moving part of the machine.
To determine this maximum speed, NMG2 provides the following measuring functions:
Measurement of maximum speed within the entire movement
Speed measurement at stop position
Measurement of the maximum speed position
If the position signal passes through a certain stop position in the selected direction, the galvanically isolated contact will trigger the machine stop and the stop time measurements will start. The position measurement values are recorded until the machine comes to a complete stop. The two displays on the measuring device will show the measured values of stop time and distance. The stop speed and time can be displayed by pressing the button. The measurement protocol will be displayed. The NMG2 ensures that the measurement starts at the set stop position and only in the selected direction of movement.
NMG2 can be used as a measuring system to measure position and speed in a variety of applications. The measured values can be transferred to a PC or laptop via RS-232 interface and can be processed with any program. Additionally, an actuator can be connected to interrupt the light curtain, so that it is not necessary to insert an additional relay into the machine connection.
Safety distance
The minimum safety distance for two-handed starts or light safety curtains is calculated as the product of the machine stop time and the specified maximum arm speed. Current safety regulations (eg. EN999) must be taken into account. Shutdown measurements must be made under the worst machine conditions to determine the maximum shutdown time and the correct safety distance.
Main features: |
Options: |
|
Dot matrix printer NMG2-2500-P Measuring range from 1250 to 30000 mm Actuator to trigger the light curtain RS-232 cable / PC program |
System specifications and features
Stop time measurement function |
|
| Measuring range | 0....5000ms |
| Resolution | 1 ms |
| Time base accuracy | 0.5 ms – 0,05% |
| Time base stability (temperature) | ±50 ppm/K |
| Relay contact compensation | The time delay of the relay contact is compensated at each measurement |
| Standstill detection | v <1...10mm/s, basic 10 mm/s |
Position measurement function |
|
| Measuring range |
-2500...+2500 mm (standard) -9999...+9999 mm (maximum) Sensor measuring range up to 30000 mm |
| Determination of breakpoint | -9999...9999 mm |
| Measuring device resolution | 1 mm (with 0,1 mm printer option) |
| Sensor resolution | 25 µm |
| Accuracy | ±0.05 % full display ±1 digit |
| Temperature influence | ±0.005% of full range / K |
Speed measurement function |
|
| Measuring range | -9999...+9999 mm/s |
| Resolution | 2,5 mm/s |
| Accuracy | ±2,5 mm/s |
General specifications |
|
| Display | 2 x 4 LED with sign |
| Trigger output | Logic signal 5V, H →L at breakpoint |
| Stop contact | NC / NO, 230 V AC / 5A |
| Circuit protection for stop contact with a fuse | 5 A slow |
| Power supply | 100...240 V AC |
| Power consumption | 30 W maximum |
| Dimensions | 425 x 325 205 mm |
| Weigh |
10.5 kg including suitcase |
| Operating temperature | 0°C ... 40 °C |
| Humidity | 80 % R.H. max, no condensation |
| Interference resistance (EMC) |
According to IEC 1000-4-2, 3, 4 |
Demonstration of system usage
Documents
-
Stop time measuring systems
(PDF / 492.01 kB)
-
Accessories for stop time measuring systems
(PDF / 207.63 kB)