The following tips can help you choose the right capacity power cables for heaters during LMS5xx laser measurement sensors installation.
LMS5xx Heater Turn On
For the LMS5xx series, heaters turn on automatically if it is too cold to turn on the motor. When the scanner is heated enough for the motor to start, the motor is then used to circulate the heated air inside the scanner. Many temperature sensors inside the scanner are used to determine if it is appropriate to enable the laser beam for measurement
The scanner enables internal heater layers within multiple PC boards if all temperature sensors register values below 5°C.
When the sensor initializes and it is too cold, the heating circuits remain enabled for a minimum of three hours in order to remove possible ice on the scanner. The heating circuits are automatically disabled after three hours if the temperature at all internal temperature sensors exceeds 10°C.
All heaters are disabled if the internal temperature rises more than 50°C. Because there are only internal temperature sensors and no external sensors, the scanner's programming can only use internal values and not the real outside temperatures.
As wind has an influence regarding temperatures, the wind speed is specified at 0m/s to 0.5 m/s for an ambient temperature of -30°C. Higher wind velocity removes the warmth from the scanner, resulting in extension of the scanner’s initialization time.
In summary, upon scanner initialization in cold temperatures, all internal heaters are enabled. Then when appropriate, the motor starts to circulate heated air. Lastly, the laser beam will be enabled for measurement.
Initialization Voltage Peak
Enabling the heaters results in not having individual surge peaks during the initialization period. This is due to use of resistive heaters.
Commissioning tests
In the Service “Userlevel” Login, a commissioning test is available which can also be used to check the heater status within LMS5xx scanners.
To enable the heaters, the outdoor rated LMS5xx scanners need a minimum voltage feed of 17.4 VDC.
This voltage level is also required for the commissioning test.
The current will be switched on for 10 seconds – (current of about 2A):
Red means that no power is connected on the heating pins, or the no-load
heater voltage is less than 17.4VDC.
Heater voltage drops to less than 16.6VDC, when the heaters are engaged. Therefore, the heaters are loading down the supply voltage.
Heater voltage is greater than 16.6V, when the heaters are engaged.
Heater Temperature Monitoring
Heater temperature monitoring may be a helpful polling command to determine scanner temperature, per the following:
It is “sRN OPcurtmpdev” to obtain the inside temperature of the scanner.
Then enter the “42040000” result into this calculator:
http://www.h-schmidt.net/FloatConverter/IEEE754.html
The answer is 33 degrees C!
If the following command response is “Error” then in conjunction with a very low internal temperature reading, can imply that the scanner is too cold to operate.
[custom_author=Don.alexander]
