User's Manual

UtiliNet® PCMCIA IWR Card User Guide 2/2/2007
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PROPRIETARY INFORMATION NOTICE:
THIS DOCUMENT CONTAINS TRADE SECRETS AND CONFIDENTIAL INFORMATION OF CELLNET AND SHALL NOT BE DUPLICATED IN
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© Cellnet 2007. All rights reserved.
Domain Routing Domain routing is an optional routing configuration for radios with 412 or later firmware. It serves to
eliminate undesirable routing choices by forcing packets to travel through a core highway of radios and not route through
areas of poor connectivity. The network is divided into “core” and “domain” radios.
Domains Seen In domain routing, core radios report information to other core radios of which of the 23 domain colors
they have direct connectivity to and how well it can see each one (unlike latency to core, it is not an accumulated value).
This information is used by core radios to route packets in a cul-de-sac situation with a packet addressed to a domain. A
higher value for domains seen is better. Values range from 0 to 3. A 0 represent no connectivity and a 3 represents good
connectivity.
Device Address The combined 10-byte WAN and LAN address of a device.
Forward Closer to the final destination of a packet.
LAN Address The 4-byte address that uniquely identifies a particular device at a radio location. A radio’s LAN address is
its serial number.
Latency to Core In domain routing, domain radios pass information among other radios of the same domain to indicate
how well they serve as paths to the core network. Latency to core is a value reporting how well a radio has connectivity to
a core radio (either directly or through other domain radios reporting their latencies to core – in which case the latency is
an accumulated value). The better the connectivity, the lower the latency. Valuesrange from 0 to 255. This provides
information for a domain radio to route through radios with lower latency when routing to core. This is necessary because
the core radios may not be in the forward direction (the direction of the packet destination). Latency to core is used in route
to core mode when geographic routing is not used.
Longitudinal Redundancy Check (LRC) An LRC is a simple security check applied to each byte of a message string. A
typical example is EXCLUSIVE-ORing each byte of a message. The EXCLUSIVE-OR is a common security check but
not very robust in terms of detecting bit errors in a multibyte message. Most LRC checks are used in conjunction with
parity (even or odd).
Luck A packet parameter that controls the maximum number of “hops” that a packet can travel. Each time the packet is
passed off to another radio, the luck parameter in the packet is decremented. If the luck reaches 0 before reaching the
destination, then the packet is discarded. This limits packet movement so that packets do not hop around forever. A luck of
255 will not be decremented and will disable this limitation for such a packet.
MAS MAS (multiple address system) is an acronym applied to 928 - 954 MHz radio systems. Specifically, the MAS
radios operate on 1 of 40 pairs of 12.5 kHz narrowband channels between 928 and 954 MHz – one transmit frequency and
a corresponding receive frequency separated by 10 to 12 MHz. The MAS systems perate with a single master transmitter
that transmits continuously and a minimum of 4 slave radios at RTU sites to “hear” the master message and respond if the
delivered message belongs or is addressed to the RTU. These systems have fast response times and are generally
considered to be direct replacements for dedicated telephone circuits.
Master Station The master station is the intelligence, that is typically centrally located, which orchestrates the system. The
Master Station is also the point of MMI (Man/Machine Interface). Other names for master station might include MTU,
SCADA host, etc.
Mood A packet parameter that controls the routing of packets. It specifies how a radio with the packet decides which radio
to pass the packet on to. Each of four moods can be individually specified, resulting in sixteen combinations. The four
mood settings are “persistent,” “quick,” “reliable,” and “scram.” When all settings are off, the mood is called “courteous.”
Mood is generally represented as a 4-bit field or nibble quantity with the bits representing the mood settings as follows: Bit
3: L3_MOOD_PERSISTENT Bit 2: L3_MOOD_QUICK Bit 1: L3_MOOD_RELIABLE Bit 0: L3_MOOD_SCRAM (not
supported)
Multipoint Radios Multipoint radios are radios that may initiate data to multiple destination addresses.
Packet Parameters The parameters in a packet that control the routing, processing, and limitations of its transmittal. The
four packet parameters are mood, priority, luck, and time-to-live.
Passive Multipoint Radios Passive multipoint radios are radios that may respond with data to multiple destination
addresses, but only after being sent a request for data from that address.
Persistent A mood packet parameter that specifies to use only battery backed radios for routing (source and destination
need NOT be battery backed).
Point Radios Point radios are radios that always transmit data to the same destination address.
Priority A packet parameter that controls the processing of a packet. A higher priority packet is processed before a lower
priority packet. A user packet can have a priority from 0 through 7 (0 being the lowest priority and 7 being the highest
priority). It is not recommended that users regularly use high priorities. A few higher prioritylevels should always be
reserved and unused for diagnostics. A non-user priority 8 is used for maintenance packets. Radios with version 413 of the
firmware limit the priority of transparent packets to a maximum of 5.
Protocol Protocol is the language used between the MTU and RTUs to communicate. Historically, each SCADA vendor