Date Code 981030
Operation Within SEL-2030
4-43
SEL-2711 Instruction Manual
O
UTGOING
G
LOBAL
D
ATA
The SEL-2030 can place user-configurable data on the network as Modbus Plus Global Data. The
SEL-2711 treats the first 32 registers of its port’s User Region as the global data. This data can
be configured using the SET M command within the SEL-2030. (See the
SEL-2030 User’s Guide
and
SEL-2020/2030 Reference Manual
for more information on using SET M to configure a
User Region.) The SEL-2711 checks this data every ½ second, which corresponds to the SET M
update interval, and sets updated global data onto the network if any of the values have changed.
Use this global data to share frequently accessed data or for expanded control capability.
I
NCOMING
G
LOBAL
D
ATA
The SEL-2711 places global data received from other nodes on the network in the D1 Region of
the local port (Port 17 or 18) database. This data can then be used within the SEL-2030 by SET
M Equations or by SEL
OGIC
Control Equations. Portions of the D1 region that correspond to non-
existent nodes or to non-existent portions of global data of existing nodes will contain the value
8000h (-32768).
However, if a node is removed from the network, the last data that it reported will remain in the D1
region of the SEL-2030. The non-data code 8000h is written only on initial configuration of the
D1 region. Once global data is written to this region, it will remain until it is over-written by new
data. The incoming global data from all nodes is written to the D1 region of the host SEL-2030
every ½ second. If global data from another node changes several times between updates, only the
latest reported value will be stored in SEL-2030 database. The following table illustrates how the
data is organized within the D1 region.
