AMTEK Version 7.4 2019-01 Page 26
©Inomatic 2017-2019
5.
SYNCHRONIZATION
5.1. AM operating principle
The AMTEK AM systems operate on the pulse-listening principle. Using the zero
crossing of the 50Hz mains frequency as a trigger, a short TX pulse of 58kHz signal is
transmitted and a receiver window is ‘opened’ after the TX pulse has stopped.
If a tag was present within detection range during the TX pulse, the resonance of this
tag will be detected in the Signal (Receiver) window and an alarm will be triggered.
A noise reference window is opened to detect the environmental noise. This signal is
compared with the signal received in the Signal window and allows the software to
properly distinguish a tag signal from a noise signal.
The figure below shows the AM operating principle (at 50Hz, with a default delay of
10μs) during one 50Hz cycle
TX Pulse
TX Pulse
1.6ms or 1.5ms (setting via
Info
Net
)
LS1
Signal window 1400
μs
LS2
Reference window 140
0μs
DEL
Detect delay 100
μs
The LS2 can be shifted individually via infoNet V5 or higher
10ms
s
20ms
DEL
11.7ms
T
X
P
ULS
E
T
X
P
ULS
E
LS
1
LS
1
LS
2
