Siemens Mobility Limited
Sopers Lane, Poole, Dorset
BH17 7ER
Version
11
Page 87 of 117
Status
Issued
Last Editor
Jeerh, Manpreet
Date
March 2020
Document
Name
WIMAG GENERAL HANDBOOK
Doc. No.
667/HB/47200/000
Copyright
©
Siemens Mobility Limited 2012. All Rights Reserved.
16.2.2 Disappearing Sensors right after commissioning
1. When the AP is set to Discovery Mode, the Access Point is temporarily set to the
default system colour code (‘FF’). This will mean the AP can ‘see’ all devices even
when they are set to other colours. However, when Traffic Dot is disconnected
the AP will revert back to the originally set ‘colour’ and will no longer communicate
to ‘other’ sensors.
2.
Ensure/confirm the ‘disappearing sensor’ is set to the same agreed system colour.
16.2.3
Wireless performance
1. Check RSSI on all sensors:
AP240
Repeater 2
nd
Gen
VSN240-F-2
-78dBm
-83dBm
VSN240 (1
st
Generation) -75dBm
-75dBm
Table 15 : Minimum Rssi Values for Appropriate Installations
The readings should be taken when there have been no vehicles across sensor
for at least 30 seconds (idle time needs to roll back to one with no vehicles on it,
f or the RSSI to refresh). If RSSI value is low, try changing geometry of SPP/AP
or RP.
2. Check RSSI on all RPs: must be a value better than -78dBm
3. Due to the nature of the communications, it is unlikely that Wifi interference will
be a significant issue. However, the LQI (link quality indicator value) will provide
some clue. If the RSSI value is in the above mentioned range (good signal
strength), the LQI value should be in the mid to high 90’s. Values outside of this
range may indicate a wireless performance issue.
4. Check for duplicate timeslots
5.
Always set ‘auto assign’ time slot at the end of the commissioning process. If
duplicate timeslots are still seen, manually change them
16.2.4 Battery level
1. 3.4V on sensors with about 1 month remaining typically
16.2.5 Active sensors are yellow or red (not green/black)
1. Confirm wireless performance is within spec (see above)
2. Check for duplicate timeslots
3.
Always set ‘auto assign’ time slot at the end of the commissioning process. If
duplicate timeslots are still seen, manually change them
16.2.6 Sticking Sensors (black)
1. Update the system configuration so that a non-default colour is used. This is
particularly pertinent if there are multiple systems within the vicinity.
