Q-FREE MD 5850 MultiReader, Руководство по установке, Страница: 19 / 21

MD 5850 Installation Manual
*S 935503232920068000 ok 32000000 245 8 - 6 2742 102103 ‘Purse =
34000. LicensePlate = XV22334. Hello world’
If the value of a parameter for some reason is unknown the location is replaced with “-“. This must also
be the case for the free-text area. For a LDR Tag the example above might be:
*S 935503232920068000 ok 32000000 245 8 230018 - - 102103 ‘Purse =
34000. LicensePlate = -. LDR Tag. Hello world’
7 TEST WITH TEST TAGS AND INSTRUMENTS
7.1 Downlink signal test
Before the test: Check that the MultiReader software is loaded and that the communication between the
MultiReader and the RSU is running properly. (Ref. chapter 6.1 and 6.2)
The downlink signal may either be tested by using a special test tag with two indication LED's, one
indicating signal level above a certain threshold and one for correct downlink data reception. Or by using
a spectrum analyser showing the signal level and modulation power spectrum.
7.1.1 Test Tag measurements.
The test tag has a red LED that lights up when the received signal level is above the “awake” threshold of
the tag. When the tag recognise correct data from the MultiReader transceiver, a green LED lights up.
No LED’s light:
The tag is not “awake”. There is no communication with the MR.
The red LED lights and the green LED is off:
The tag is “awake”. This indicates that the tag is receiving data frames, but the data is incomprehensible
so the tag does not respond. This indicate that the signal to noise ratio is too low.
Both the red and green LED’s light:
The tag is “awake”, and it is responding the data frames. The system downlink is OK.
7.1.2 Measuring the MultiReader footprint with a test tag.
Use the test Tag to find the MR’s footprint:
•
Directly towards MR direction (starting farthest off from MR):
Point the test tag towards the MR and hold it 1 m above the ground. Start walking right towards
the MR. When the red LED lights, mark this point (1) (example shown in fig.7.1) on the ground.
Continue towards MR, and when the green LED starts blinking, put a mark (2) on the ground.
Carry on towards MR and notice that both LED’s light. When the green LED starts blinking, put a
mark (3) on the ground. Proceed until the red LED shuts down. Put a mark (4) here.
•
Sideways direction , (starting in the centre of the footprint):
Point the test tag towards the MR and hold it 1 m above the ground. Both LED’s are light. Start
moving the tag sideways until the green start blinking. Put a mark (5) on the ground. Continue
sideways until both LED’s shut down. Put a mark (6) here.
Start from centre and move sideways to the other direction. Use the same procedure as above. Put
two marks (7 and 8) here.
Q-Free
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ASA 645-054-1999 rev.4 18 of 20