EZT-570S User Manual
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The most commonly overlooked source of problems is cabling. Not all cables are created equal.
Electrical noise generated by factory equipment or other electrical equipment in the area, could easily
corrupt transmitted data over the network and cause devices to ‘lock up’ or shut down the VNC
server, both of which then requires the EZT-570S to be shut down and restarted to clear the problem.
Select the right cable for the environment. Shielded twisted pair (STP) cable is naturally more noise
immune and is preferable to unshielded twisted pair or UTP in noisy situations. STP should have at
least 40dB CMRR and less than 0.1pF capacitance unbalance per foot. Ground STP cable, making
sure the ground is connected only at one end. CAT5 STP patch panels normally provide a grounding
strip or bar. Hubs and switches don’t provide grounding, use cables.
It’s wise to be pessimistic about a cable’s ability to reject noise from 230 VAC and 460 VAC power
lines and electrically ‘noisy’ equipment in the area. Capacitance imbalance in cables greater than
70pF per 100m can introduce harmonic distortion, resulting in bit errors. The cost of cable is quite
small compared to total equipment cost, so if you’re looking to save money, this is not a place to do it.
Choose a well-designed cable to minimize bit-error rate after installation, and that will give faster
throughput with fewer glitches.
9.3.2
Configuring the EZT-570S Network
In order to connect to the VNC server or web server of the EZT-570S, you will need to know the IP
address of the EZT-570S on the network. It is important to note that if using DHCP in your network
router, the address may change on re-power requiring you to access the EZT-570S directly in order
to obtain the new IP address. This could result in VNC/web server connection issues if the address
regularly changes.
Therefore, it is recommended that the IP address for the EZT-570S be assigned as a fixed (static)
address. This insures that the address will not change once it has been set. This can be done in one
of two ways. The first is by setting up the control LAN router to assign the same IP address
whenever it detects the EZT-570S on the network via its own identifier; it’s MAC address.
The other option is to configure the EZT-570S to use a fixed IP address and disable the DHCP
addressing function of its network interface. When using this method, it is important to make sure
that the address being assigned to the EZT-570S is not used by any other device on the network. If
another device is using the same address, the VNC and web server interfaces will not function
correctly. It is recommended that this method of static IP assignment be used as it removes the IP
address lease renewal process that would be performed by the control LAN router if DHCP was used.
The lease renewal process performed by the control LAN router can cause the VNC server in the
EZT-570S to shut down due to an issue in the renewal process. It could be caused by something in
the router firmware or configuration of the router itself. Due to the numerous brands and models of
routers available, and the dynamic nature of their use, attempting to resolve the issue is beyond the
scope of this manual. Therefore, the use of static IP addressing removes this from the equation,
providing the most robust network solution.
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