Specifications

Waters Network Systems User’s Manual Page 11
PS-2126M-POE
Once the self test is performed, the bootloader will load the firmware into the memory, which
takes about 30 seconds. The switch will flash the LEDs once and automatically perform a self
test.
3.9 Installing Chassis to a 19-inch Wiring Closet Rail
Caution: Allow a proper spacing and proper air ventilation for the cooling fan at both sides of
the chassis.
 Wear a grounding device for electrostatic discharge.
 Screw the mounting accessory to the front side of the switch
 Place the chassis into the 19-inch wiring closet rail. Secure the chassis with the screws.
3.10 Switch Topology
Theoretically, the switch partitions the collision domain for each port so you may link switches
without limitations. However, network extension (cascading levels & overall diameter) must
follow IEEE 802.3/802.3u/802.3z and other 802.1 series protocol specifications, in which the
limitations are the timing requirement from physical signals defined by 802.3 series specification
of Media Access Control (MAC) and PHY, and layer 2 protocols such as 802.1d, 802.1q, and
LACP.
The following table describes the cable and devices’ bit-time delay (round trip):
1000Base-X TP, Fiber 100Base-TX TP 100Base-FX Fiber
Round trip Delay: 4096 Round trip Delay: 512
CAT5 11.12/m CAT5 1.12/m Fiber Cable: 1.0/m
Fiber 10.10/m TP to fiber converter: 56
Bit time unit: 1ns (1sec./1000 Mega bit)
Bit time unit: 0.01μs (1sec./100 Mega bit)
Table 3-2
Sum up all elements’ bit-time delay and the overall bit-time delay of wires/devices must be
within Round Trip Delay (bit times) in a half-duplex network segment (collision domain). This will
not be applied for full duplex operation. You may use the TP-Fiber module to extend the TP
node distance over fiber optic and provide the long haul connection.
A hierarchical network with minimum levels of switching may reduce the timing delay between
server and client station. Basically, with this approach, it will minimize the number of switches in
any one path; will lower the possibility of network loop and will improve network efficiency. If
more than two switches are connected in the same network, select one switch as Level 1 switch
and connect all other switches to it at Level 2. It is recommended to connect the Server/Host to
the Level 1 switch. This generally applies if no VLAN or other special requirements are applied.
Example 1: All switch ports are in the same local area network. All ports can access
each other (See Figure 3.3).