Lantronix
SISTP10x0-3xx-LRT Install Guide
33733 Rev. G
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Caution
: The switch is an indoor device. If it is to be used with outdoor devices such as outdoor IP cameras or
outdoor Wi-Fi APs, then you are strongly suggested to install a surge protector or surge suppressor in order to
protect the switch. The switch is compliant with 802.3at in Environment A when using an isolated power supply.
For 802.3at Environment B applications, i.e. building to building, copper to copper endpoint connections: 1) use
an Ethernet network isolator module (PoE disabled), or 2) use mid-span injector (s), e.g. MIL-L100i, L1000i-at,
between this switch’s PSE port and link partner PD port.
Mode A vs. Mode B
Alternative A, also known as Mode A, uses the data pairs of an Ethernet link to deliver power. Data Pairs include
pins 1,2 and 3,6. PSEs using Mode A supply a positive voltage to pins 1 and 2.
Alternative B, also known as Mode B, uses the spare pairs to deliver power. Spare Pairs include pins 4,5 and 7,8.
802.3af/at Standard “compliant” vs "compatible" PDs
Knowing the difference between PoE "compliant" and "compatible" devices can help avoid interoperability and
connectivity issues. Compliant PoE devices and compatible PoE devices are not held to the same 802.3af/at
standard:
•
802.3af/at “compliant” PDs fulfill the IEEE strict requirement to support both Mode A and Mode B power
modes.
•
802.3af/at "compatible" PDs typically can provide power using only Mode B.
Typical PD Power Requirements
•
1.8 Watts: Lantronix’ M/GE-ISW-SFP-01-PD (Class 1 Powered Device (0.44 Watts - 3.84 Watts).
•
13W: IP Camera, VoIP Phone, Wireless Access Point, Networked Audio.
•
30W: IP Telephone, WiMAX Access Point, PTZ Camera, Remote Computer Terminal.
•
60W : Door Access System, Video Phone, Thin Client.
•
100W: Digital Signage Display, Point-of-Sale System, LCD TV, Computer Monitor.
•
200W: Larger TV, Larger Display, Larger Monitor, Laptop.
After eliminating basic network factors, ask your PD vendor for the PD’s power supply mode and polarities
supported and exact power consumption.
Calculate PoE Power Budget
To calculate how many 802.3at devices the unit supports, divide the Total PoE Budget (130 Watts) by 30 Watts.
To calculate the maximum number of 802.3af devices, divide the Total PoE Budget (130 Watts) by 15.4 Watts.
Mixing POE and Non-POE Devices
You can mix POE and non-POE devices on the same POE switch (i.e., you can put PCs on the same PoE switch as a
SIP phone or a VOIP phone). The PSE (your switch) will only send power if requested by the PD.