Xylem 19-001-350R2 PACE Integrated Pump Controller Human Machine Interface (HMI) for the Silent Storm VFD Pumping System – Technician Guide - Manual (Page 50)

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Appendix H – General Networking and Router Configuration
Discussion:
Regarding the requirement for a fixed IP address: This is not a requirement of the Flowtronex
Pace control system. This is required so the user attempting to access the system remotely can
find the machine on the internet. Without a fixed IP address, the computer is at one of
4,228,250,625 theoretically possible addresses, though usually addresses are assigned within a
specific range of a few thousand. The internet service provider typically assigned an IP address
dynamically when the computer connects. The dynamic IP address won’t affect messaging out,
only accessing the station from the outside in. There are for-pay services for keeping track of
your IP address via domain name, though these also come at a cost.
There are also often complications related to getting access to the router through any on-site
networks. There tend to be one or two routers between the pump station router and “the
internet”, and each of those routers has to “pass through” or “forward” messages to the pump
station router. This is a configuration issue for the routers in the chain and while not a
complicated setup, communicating with and getting approval from local IT departments can be
difficult.
On most systems, we have a single pump station the user needs to connect to remotely. If port
80 messages can be sent to our router, the user can access his pump station.
For example: Lets say their router is set up to pass requests to it (say it’s 76.199.123.234) directly
to the pump station router. The user types in:http://76.199.123.234
Their router forwards the message: http://192.168.1.1:80 along with the request data. The pump
station router passes through port 80 traffic to 192.168.1.15 on port 80.
The HMI responds with a web connection. Anything that comes in to their router requesting data
from port 80, get’s “routed” to the pump station router on port 80, and the pump station router
routes it to the HMI.
In another example, the IT router already passes traffic to another web server on port 80, so we
can’t use port 80. To work around this problem, IT can set their router up to pass port 81 traffic to
us on port 80. We still route port 80 traffic to the HMI on port 80 at 192.168.1.15. Again, the web
page on the HMI works, though the user will need to access the page by typing in:
http://76.199.123.234:81 (The IP addresses used in these examples are fictitious, except for the
“pump station router” which has its LAN side IP address set to 192.168.1.1, and all equipment on
the LAN side of the router is in the 192.168.1.X range.
If there are two or more HMIs on site, the site router would have to pass multiple ports to our
router, normally 80,81,82,83. We would then route port 80 traffic to 192.168.1.15, 81 to
192.168.1.16, 82 to 192.168.1.17, etc. They would just have to set their routing table up to give
us all messages for port 80 to us at port 80, all messages for port 81 to us at port 81, etc. This
idea can cascade to several routers. Also, in order for Flowtronex to remotely configure the
router, port 8080 is used, but no routing is provided in the pump station router since the router
itself provides the service (the router user name and password are labeled on the back of the
router).
Router 1 Router 2 Pump Station Router
WAN 76.199.50.60 10.92.168.10 192.168.0.12
LAN 10.92.168.1 192.168.0.1 192.168.1.1
Port
Forwarding 80->10.92.168.10:80 80->192.168.0.12:80 80->192.168.1.15:80
8080->10.92.168.10:8080 8080->192.168.0.12:8080 None (Router Configuration)