Motorola V186 - Cell Phone - GSM System Planner Manual page 106

4. IP Gateway connected to LAN. An IP Gateway (IPGW) serves as a front-end for
a TCP/IP-based SCADA central and enables it to communicate with remote
RTUs. The IPGW uses a direct LAN connection to the radio infrastructure. It
cannot be connected with a packet IP Ports (IP LAN/WAN ports) data
modem/radio over PPP. For this purpose an RTU (with packet data radio/modem)
is needed with RS232/RS485 to connect them.
Note: Although the ACE3600 RTU has Ethernet ports, it does not have the IP Gateway
functionality.
Auto-Negotiation Note: The ACE3600 Ethernet port performs one Auto-Negotiation
procedure upon startup. It is recommended to configure the Ethernet port of the device
connected to the ACE3600 Ethernet port (e.g. switch, etc.) to Auto-Negotiation mode. If
the Auto-Negotiation fails, the ACE3600 Ethernet port default is 10 Mbps half-duplex.
Broadcast and Setcalls
Most wireless packet data networks do no support broadcast IP. When transmitting a
group call (Site 0), a separate frame is transmitted to each site specified in the IP
Conversion Table over UDP/IP. If broadcast IP exists, then this IP can be specified in the
IP Conversion Table under Site 0 with the proper link ID (port). Sending to Site 0 with
that link ID will transmit a single message, through that port, to all RTUs over UDP/IP
using that address. Note that in ASTRO IV&D, GPRS, TETRA and most wireless media,
this is not supported, so a separate message is transmitted to each site. It is preferable to
transmit to each site separately, rather than send this setcall, with a delay around 100-300
milliseconds between one transmission and another.
New Features for MDLC over IP in ACE3600
The following features are available in ACE3600 that are not available in legacy
MOSCAD RTUs and IP Gateway. These features apply to Ethernet static IP address,
Ethernet DHCP, and RS232 PPP port types.
Multiple IP Ports
The user can specify more than one MDLC over IP port in ACE3600. The IP Conversion
Table includes a link ID column which enables the same ACE3600 site ID to appear
several times, with a different link ID and the same IP address.
In some cases, it is necessary to have more than one link ID per MDLC over IP port. For
example, if RTU 1 has a single Ethernet MDLC over IP port, and it communicates with
another RTU that has two (or more) MDLC over IP ports LINE1 and LINE2. In this case
RTU 1 must have its MDLC over IP port assigned with two link IDs: LINE1 and LINE2.
This will enable direct communication to RTU 2 LINE1 port or to RTU 2 LINE2 port.
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Communications