Modbus User Map - GE Multilin W650 Instruction Manual

5.2 PRODUCT SETUP
The W650 supports the Simple Network Time Protocol specified in RFC-2030. With SNTP, the W650 can obtain the clock
time over an Ethernet network. The W650 acts as an SNTP client to receive time values from an SNTP/NTP server, usually
a dedicated product using a GPS receiver to provide an accurate time. Three different modes of SNTP operation are
supported. These modes are unicast, broadcast and anycast.
If SNTP functionality is enabled at the same time as an IRIG-B source is connected to theW650, the IRIG-B signal provides
the time value to the W650 clock for as long as a valid signal is present. If the IRIG-B signal is removed, the time obtained
from the SNTP server is used.
To use SNTP in unicast mode, Server IP Oct1..4 must be set to the SNTP/NTP server IP address. Once this address is set
and theFunction setting is "UNICAST", the W650 attempts to obtain time values from the SNTP/NTP server. Since many
time values are obtained and averaged, it generally takes forty seconds until the W650 clock is synchronized with the
SNTP/NTP server. It may take up to one minute for the W650 to signal an SNTP FAIL state if the server is offline.
To use SNTP in broadcast mode, set the Function setting to "BROADCAST". The W650 then listens to SNTP messages
sent to the "all ones" broadcast address for the subnet. The W650 waits up to eighteen minutes (>1024 seconds) without
receiving an SNTP broadcast message before signaling an SNTP FAIL state.
To use SNTP in anycast mode, set the Function setting to "ANYCAST". Anycast mode is designed for use with a set of
cooperating servers whose addresses are not known beforehand by the client. The W650 sends a request to a multicast
group address aasigned by IANA for NTP protocol. This address is 224.0.1.1 and a group of SNTP/NTP servers listens to
it. Upon receiving a request each server sends a unicast response to the SNTP/NTP client. The W650 relay binds to the
first unicast message received from any server. Then it continues operating with SNTP/NTP server in unicast mode. Any
further responses from other SNTP/NTP servers are ignored. In unicast mode of operation the chosen time server can go
offline, in that case it takes about one minute for the W650 to signal an SNTP FAIL state and to switch again to anycast
mode to try to find another time server. In anycast mode the W650 tries to send multicast messages up to five minutes
before signaling an SNTP FAIL state.
The W650 relay does not support the multicast mode of SNTP functionality.
5
The ModBus user map definition. 256 records, selectable from the complete relay ModBus map, form the ModBus user
map. For more detailed information go to appendix B in this manual.
Table 5–9: MODBUS USER MAP SETTINGS
PRODUCT SETUP > MODBUS USER MAP
Name
Address 00
Address 01
...
Address 254
Address 255
5-6
Default Value Step
0000
0000
0000
0000
W650 Wind Generator Protection System
5 SETTINGS

5.2.2 MODBUS USER MAP

Range
[0000 : FFFF]
[0000 : FFFF]
...
[0000 : FFFF]
[0000 : FFFF]
GEK-113032A