Model 914-X Series Modular Multiplexer System User Manual
Focal Technologies Corporation
Page 4-5
A Moog Inc. Company
Document Number: 914-0601-00
Rev.
5.0
4.5
914-HDE Ethernet Port
The 914-HDE provides an un-switched, low latency 10/100/1000 BASE-T(X) Ethernet link through the optical port.
The part is default configured for 10/100 BASE-T(X) in the L1 version, and 10/100/1000 BASE-T(X) for M1 and H1
versions. Auto-negotiate settings can be accessed via the Model 914 Diagnostic GUI. A standard 8P8C (RJ45)
modular jack provides the mechanical interface for the Ethernet port. The port is auto MDI/MDIX capable, and
supports jumbo frames up to 9000 bytes.
An optional “Link Fault Pass Through” can be enabled. This feature will disconnect the Ethernet link if the far side
is not linked. Therefore the system must be linked on both sides for the Ethernet link to be established. Enabling or
disabling this feature is done through the diagnostic GUI.
Figure 4-7: Ethernet Port
Integrated LEDs show Ethernet Link Status as shown in Table 4-5.
Table 4-5: Ethernet LEDs
LED Status
Function
Green
Yellow
OFF
OFF
No Link
ON
OFF
Linked at either 1000 BASE-T or 10 BASE-T
ON
ON
Linked at 100 BASE-TX
FLASHING
OFF
Link Activity at either 1000 BASE-T or 10 BASE-T
FLASHING
ON
Link Activity at 100 BASE-TX
End-to-end latency through the multiplexer is a calculation adding a fixed electronic latency to the Ethernet frame
time which is a function of the frame length, and the optical latency which is a function of distance. Adding all three
together gives a total latency figure.
Table 4-6: Ethernet Latency
Latency Component / Link Speed
10 Mb/s
100 Mb/s
1000 Mb/s
FEL (Fixed Electronic Latency)
30
s
6
s
3
s
FT (Frame Time)
# Bytes * 0.8
s
# Bytes * 0.08
s
# Bytes * 0.008
s
OL (Optical Latency)
5
s / km
5
s / km
5
s / km
Latency = FEL + FT + OL
