User's Manual

Table Of Contents
MDS 05-2708A01, Rev. D MDS TransNET I&O Guide 63
Operational Influences—Hoptime & SAF
The synchronization period is influenced by two parameters’
values—HOPTIME and SAF (Store-and-Forward). Table 26 shows several
configurations and the associated synchronization period value.
9.9 MIRRORED BITS™ Protocol Support
TransNET radios are compatible with Schweitzer’s Mirrored Bits MB8
protocol, provided complementary firmware (06-4045A01) is installed in all
network radios. A detailed application guide (AG2003-07) is available from
Schweitzer Engineering Labs Web site, www.SELinc.com/aglist.htm, or
from Microwave Data Systems’ Web site at www.microwavedata.com.
9.10 Seamless Mode Emulation
The RXD command assumes the payload message will be ready for transmis-
sion after the delay period has expired. If there is a chance the payload data
may be delayed, it is recommended to use the BUFF(er) command to make
sure the entire message is received before delivery is started. The BUFF
command provides a highly-reliable seamless operating mode, but can be
very slow to start, especially if it waits for the reception of long messages
before passing on the message.
9.11 Full-Duplex Emulation
If your system design needs to support PTP or Point-to-Multipoint applica-
tions and your communications must appear to be full-duplex to the
connected devices, set the Master to CSADDR xxxxx (where xxxxx is the
Network Address (
ADDR). This will place the system in a time-division
duplex mode (TDD). The radio system will appear to be full-duplex to the
connected devices, but actually operates half-duplex over the radio link. Data
is buffered by the transmitting side until it is its turn to transmit. Throughput
will be approximately 1/2 of the
DATA interface rate.
9.12 Co-Located and Close-Proximity Masters
If your requirements call for multiple TransNET networks at the same loca-
tion, you need to ensure that interference between the systems in minimized
to prevent overload that will diminish the performance of the radios. Tradi-
tionally, vertical separation of the antennas of co-located radios was required
Table 26. Synchronization Period versus
Hoptime and SAF Settings
Sync Period Hoptime Value SAF
441 ms 7 OFF
1.8 sec 28 OFF
3.5 sec 28 ON