Tech Briefs Magazine - May 2022 - PIT-10

High-Speed Machine Vision
Because CXPoF combines the CXP-12
standard with optical fiber, this upgraded
standard eliminates the need for multiple
CXP-6 copper cables. Vision Research recently
incorporated this technology into
its latest MV camera, the Phantom S991,
which requires just two fiber cables as opposed
to the 16 copper cables required by
its predecessor, the Phantom S990. The
Phantom S991 includes an 8-bit output
option to provide higher frame rates in
the larger resolutions and reduce data
throughput. It also has resolution increments
of 128 (horizontal) × 8 (vertical),
allowing users to maximize resolution for
the required frame rate.
The Phantom S991 provides the same throughput
as its predecessor, the Phantom S990, but it
uses only two QSFP+ transceiver modules and
fiber cables.
The more recent CXP-12 consists of a
12.5 Gbps link over a coaxial copper cable,
while four CXP-12 links can easily
achieve bandwidths of 50 Gbps with link
aggregation. In terms of connectors,
CXP-6 uses DIN 1.0/2.3 connectors with
a push-pull latching system, while CXP12
uses Micro-BNC (HD-BNC) connectors
with trusted push-and-turn, bayonet-style
positive locks for quick and easy
connection/disconnection.
Achieving Higher Throughput
with CXPoF
An add-on to the more recent CoaXPress
2.0 specification, CoaXPress-over-Fiber
(CXPoF) provides a way to run an unmodified
CXP-12 protocol over a standard
Ethernet connection including fiber optics.
In other words, it uses standard electronics,
connectors and cables designed
for Ethernet, but the protocol is CoaXPress
instead of Ethernet or GigE Vision.
Interface
GigE Vision
USB3
Camera Link
CXP-6
CXP-12
Bandwidth
1.0 Gbps
5.0 Gbps
Base: 2.0 Gbps
80-bit: 6.8 Gbps
1x: 6.2 Gbps
2x: 12.5 Gbps
4x: 25.0 Gbps
1x: 12.5 Gbps
2x: 25.0 Gbps
4x: 50.0 Gbps
Comparison of High-Speed Camera Interfaces
10
In terms of bandwidth, CXPoF achieves
4 × 10 Gbps on a single Quad Small
Form-Factor Pluggable (QSFP+) transceiver
module for a total of 40 Gbps per camera
- the same net bandwidth as four
CXP-12 links over four copper coaxial cables.
The Phantom S991, for example, provides
the same throughput as the S990, but
it uses only two QSFP+ transceiver modules
and fiber cables. The S991 also uses
Kintex®
UltraScale+™ FPGA with Euresys
CXP-12 IP Core and CoF Bridge. Within
the camera, this bridge converts CoaXPress
packets to XGMII (10 Gigabit Media-Independent
Interface) packets going
toward the Ethernet Physical Coding Sublayer
(PCS) or Physical Medium Attachment
(PMA) block. Within the frame grabber,
the bridge also converts the XGMII
packets to CoaXPress packets.
The Benefits of CXPoF
The CoaXPress standard has been successful
due to its unique combination of
high bandwidth, low latency, high stability,
and excellent reliability. When integrated
into high-speed cameras, it improves
the data transfer process, enabling
Frame Rate
4MP Camera
25 fps
90 fps
-
180 fps
~ 150 fps
~ 300 fps
~ 600 fps
~ 300 fps
~ 600 fps
~ 1200 fps
40 m
40 m
Cable Length
100 m
3 ~ 7m
6 ~ 10 m
CoaXPress Benefits
at a Glance
* High-speed data rates: up to 12.5
Gbps over a single coax cable and
scalable for multiple cables. Four
cables achieve 50 Gbps, while
eight cables achieve 100 Gbps.
* Long cable lengths in excess of
100 meters at 3.125 Gbps and 35
meters at 12.5 Gbps.
* Real-time behavior with fixed,
low-latency transmission.
* Precise triggering capabilities.
* Single cable integration for image
data, communication, control and
power.
* Cost-effective cabling options.
users to obtain high-quality images at
extremely fast frame rates.
CoaXPress-over-Fiber keeps and
builds on these benefits. For example,
because CXPoF is an add-on to the existing
CXP standard, high-speed imaging
experts can leverage the same programming
when upgrading their
camera. Because it uses Ethernet components,
CXPoF also only requires standard
Ethernet connectors and cables,
keeping costs low. At the same time, it
takes advantage of the " free " evolution
of Ethernet as it progresses toward
higher bandwidths - like the eventual
400 Gigabit Ethernet.
In addition to reaping the benefits associated
with Ethernet, users can enjoy
all the advantages of fiber optics. These
cables are small and lightweight. Fiber
optic technology can also handle higher
bandwidths compared to copper cables,
and it is immune to electrical noise - an
ideal characteristic for noisy production
floors and medical applications.
CXPoF opens the door to new highspeed
MV applications while, at the same
time, simplifying those applications
where high-speed MV is already in use.
For example:
* CXPoF eliminates complex, error-prone
repeaters. Prior to the CXP12
standard, users had to deploy expensive
repeaters to translate the
CXP-6 standard into fiber, driving up
costs by several thousands of dollars.
This setup also created very bulky cable
interfaces with many potential points
of failure. CXPoF simplifies this setup,
eliminating the need for repeaters and
their associated failure points.
Photonics & Imaging Technology, May 2022
PIT Machine Vision Feature 0522_1.indd 10
Cov
ToC
4/18/22 12:39 PM
http://info.hotims.com/82321-831
Tech Briefs Magazine - May 2022

Table of Contents for the Digital Edition of Tech Briefs Magazine - May 2022
