Example Of An Application "Setting The Power Ramp And Rssi Threshold - Siemens SIMATIC Ident Operating Manual

6.4 Example of an application "Setting the Power Ramp and RSSI
Threshold"
Aim
The aim is to increase the robustness of the reading point by using the Power Ramp in read
mode and using the RSSI Threshold to avoid overshoot.
Background
The Power Ramp algorithm is useful when a transponder needs to be identified with an
output power as low as possible (inventory). This power can vary by several dB between
inventories taken at different times.
The use of an RSSI threshold is a practical solution when an RSSI value is detected at a
reading point for the transponders to be identified that is always higher than the minimum
value (RSSI Threshold) and other transponders outside the reading point are always below
this threshold.
Procedure
To evaluate an optimized parameter assignment of Power Ramp and RSSI Threshold, use
the "Tag List" tab. Use the "RSSI" tab to assign the RSSI threshold values (RSSI Threshold
ANT1, RSSI Threshold ANT2). To make settings for Power Ramp, use the "Power Ramp"
tab.
The following values have proved useful in typical use cases:
● Monitor the RSSI values of the transponders in the Tag List. Note down the typical RSSI
● Set Boost Max ANT1 / Boost Max ANT2 to 8 (+2 dB), Boost Step Size ANT1 / Boost Step
SIMATIC RF-DIAG
Operating Manual, 09/2012, C79000-G8976-C292-01

6.4 Example of an application "Setting the Power Ramp and RSSI Threshold"

value of the required transponder (overreach). Set the value of RSSI Threshold ANT1 /
RSSI Threshold ANT2 half way between the two obtained values. In many situations, this
results in an RSSI Threshold of approximately 88% of the RSSI value of the required
transponder.
Size ANT2 to 4 (1 dB) and Boost Threshold ANT1 / Boost Threshold AN2 to 2 (2
inventories).
Application Examples
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