Using instructions

1 Cable connecting definitions

Red line         ——       +5V

Black line       ——       PGND

Yellow line     ——       T/R-

Green line      ——       T/R+

Blue line        ——       DGND

       2 Operating Steps

       2.1 Connect a sensor to the serial port of computer (or other device which have serial ports) and the power port of adapter with special data cable.

              2.2 Trigger Measuring

                     2.2.1 Send the command “O” (ASCII) or “0X4F” (HEX) by computer to turn on the sensor. Then the sensor will turn on the laser and prepare for working, and return the data “FF 00 0A 0A 0A 00” to the serial interface.

                     2.2.2 Send the command “O” (ASCII) or “0X4F” (HEX) again to the sensor to start to measure distance. The sensor will return the measured data like “FF XX XX XX XX XX” to the serial interface and turn off the laser when it finished one time measurement.

                     2.2.3 Send the command “U” (ASCII) or “0X55” (HEX) to turn off the sensor.

              2.3 Continuous Measuring

                     2.3.1 Send the command “O” (ASCII) or “0X4F” (HEX) by computer to turn on the sensor. Then the sensor will turn on the laser and prepare for working, and return the data “FF 00 0A 0A 0A 00” to the serial interface

                     2.3.2 Send the command “C” (ASCII) or “0X43” (HEX) to the sensor. The sensor will begin to measure continuously after 3 seconds when it got the order, and return the data continuously like “FF XX XX XX XX XX”. If the sensor couldn’t get any available data, it will return “FF 00 0A 0A 0A 00” to the serial interface.

                     2.3.3 Send the command “U” (ASCII) or “0X55” (HEX) to turn off the whole sensor (include both of laser unit and measuring unit).

 Input and output

       1 Data format for RS232 serial communication

       Baud rate: 9600 bps , Data bits: 8 , Stop bit: 1 , Parity bit: None

       2 RS232 input frame format

There is only one byte in every input frame. The user could send different commands to the sensor for different purpose, the functions of command are shown in the following table.

3 RS232 output frame format

There is 6 bytes in every output frame, the frame header is 0XFF, MSB is A, LSB is E. Their orders are shown in this table here.

The mapping table of HEX and ASCII codes:

Display Notices

All display notices are either displayed with “FF DA 00 XX XX XX”. The following errors can be corrected.

On what kind of targets can be measured?

All opaque targets can be measured. Reliable measurements on transparent targets are not possible.

How is the measurement rate influenced?

The measurement rate is influenced by the target. If the laser light is well reflected by the target, fast measurement rates can be achieved (up to 0.15s in tracking mode).

Does dust influence the measuring process?

If dust overcasts the main part of the laser beam, then your
measurement will be influenced in a negative way. However, this situation can only be found in extreme dusty environment like cement hopper etc.

Is it possible to measure to a moving target?

Yes it is possible. The measured distance is the mean value between the distance at start and end of the measuring process.

What is the Measuring Accuracy?

The measuring accuracy corresponds to the ISO-recommendation ISO/R 1938-1971 with a statistical confidence level of 95% (i.e. ±twice the standard deviation, refer to diagram right. The typical measuring accuracy relates to average conditions and is ±1.5mm for the DLS(H) 15 and ±3.0mm for the DLS(H) 30. This is valid for the tracking mode.

The maximum measuring error relates to unfavorable conditions such as:

• highly-reflecting surfaces (e.g. reflector tapes)
• operating at the limits of the permitted temperature range, adaptation to ambient temperature interrupted
• very bright ambient conditions, strong heat shimmer

The maximum measuring error can be up to ± 2 mm for the DLS(H) 15 and ± 5 mm for the DLS(H) 30.

The DLS-A devices do not compensate changes of the environment conditions. If the environment conditions differ from 20°C, 60% rel. humidity and 953mbar air pressure, the accuracy can be influenced if the measuring distances is longer as 150m.

The effects caused by environment condition are described in:

B.Edlen: “The Refractive Index of Air, Metrologia 2”, 71-80 (1966)

Is the Laser Light eye safe?

Class II lasers are low power (< 1mW), visible light lasers that could possibly cause damage to a person's eyes. Some examples of Class II laser uses are: classroom demonstrations, laser pointers, aiming devices and range finding equipment. If class II Laser beams are directly viewed for long periods of time (i.e. > 15 minutes) damage to the eyes could result. Avoid looking into a Class II Laser beam or pointing a Class II laser beam into another person's eyes. Avoid viewing Class II laser beams with telescopic devices. Realize that the bright light of a Class II Laser beam into your eyes will cause a normal reaction to look away or close your eyes. This response is expected to protect you from Class II Laser damage to the eyes.

Can I connect the DLS device to a Siemens PLC?

Yes, you can connect a DLS device with the RS422 interface to a Siemens S7 PLC. Please find a detailed example in the application section. (AN2010)