mirror of
https://github.com/uhi22/pyPLC.git
synced 2024-11-10 01:05:42 +00:00
77 lines
2.4 KiB
Markdown
77 lines
2.4 KiB
Markdown
# PLC signal amplitudes
|
|
|
|
To have comparable results, we measure the peak-to-peak voltage of the preamble of the homeplug packet.
|
|
|
|
1. Homeplug modem with AR7420, supplied by 5V
|
|
10Vpp at the transformer
|
|
|
|
2. Homeplug modem with AR7420, supplied by 5V, with 150ohm series resistor between transformer and CP.
|
|
Foccci v3 (including transformer with RIK10, 2x5 turns) connected via 1m twisted pair.
|
|
3Vpp at the CP line
|
|
|
|
3. Like 2, but in the homeplug modem two additional series resistors 680ohms in the transmit path, between
|
|
the power amplifier and the transformer.
|
|
|
|
- EVSE packet: 250mVpp at the CP line
|
|
- Foccci packet: 500mVpp at the CP line
|
|
|
|
4. Like 3, but in the homeplug modem the two 680ohm in serial and a 10ohm in parallel to the transformer.
|
|
|
|
- Foccci packet: 500mVpp at the CP line (no change, normal)
|
|
- EVSE packet: hardly measurable, in the 20mVpp range.
|
|
- Communication still works perfect.
|
|
|
|
5. Compleo 20kW triple charger
|
|
|
|
Sends very loud packets, even if no vehicle is connected.
|
|
17Vpp
|
|
|
|
6. ISO 15118-3
|
|
|
|
On both, EVSE side and EV side of the charging cable, the typical voltage is
|
|
1.3Vpp.
|
|
This is specified as "power spectral density" of typical -75dBm/Hz at 1.8MHz to 30MHz, receiver band width 9kHz with 50 ohms.
|
|
|
|
Example states the following levels:
|
|
- Transceiver output: -72dBm/Hz
|
|
- CP on EVSE: -76dBm/Hz
|
|
- CP on PEV: -78dBm/Hz
|
|
- Transceiver modem input: -81dBm/Hz
|
|
This would be 9dB between transmitter output and receiver input.
|
|
|
|
7. Output of the QCA7005
|
|
|
|
4Vpp. Each output (TX+ and TX-) sit at ~1.6V statically, and move 1V up and 1V down. So the differential voltage
|
|
reaches from -2V to +2V, which is 4Vpp.
|
|
|
|
8. Foccci 5.1 transmit level
|
|
|
|
with 120ohm termination
|
|
|
|
270mVpp
|
|
|
|
9. Foccci 5.1 receive limit test
|
|
|
|
- Foccci sees the EVSE, starting to become instable, if 400mVpp -36dB. This is 400mVpp / 64 = 6mVpp.
|
|
- Foccci sees single messages, if 400mVpp -42dB. This is 3mV.
|
|
- Foccci does not see the EVSE (modem goes to sleep) if 400mVpp -44dB. This is 400mVpp/158 = 2.5mVpp.
|
|
|
|
10. Foccci 5.1 transformerless patch, R25=100ohms, receive limit
|
|
|
|
- 400mV -32dB stable connection.
|
|
- 400mV -38dB still works, starting to become instable.
|
|
- 400mV -44dB sometimes modem sleep, sometimes not.
|
|
- 400mV -50dB modem sleep.
|
|
|
|
11. Foccci 5.1 transformerless patch, R25=100ohms, transmit level
|
|
|
|
210mVpp
|
|
|
|
|
|
# Attenuation calculator
|
|
|
|
https://www.digikey.de/de/resources/conversion-calculators/conversion-calculator-attenuator
|
|
|
|
* -6dB is half voltage
|
|
* -12dB is quater voltage
|
|
* -20dB is tenth voltage
|