User`s manual

ioLogik E2260 User’s Manual Active OPC Server Lite
5-3
Active OPC Server Lite – From Pull to Push
When first looking up the I/O divices’ Modbus table, users need to create one tag within 19 or
more steps including specifying the IP address, selection of the protocols, and define the data type.
The procedure is repeated over and over again until all the devices and tags are created. A
technician can expect to take 1 minute to create just one tag. But what if there are 400 tags in the
OPC system? Also, the more tags are used, the higher CPU loading will be taken.
The general OPC also requires the connected I/O devices to use fixed IP address, if there are
applications running on a public network (usually dynamic IPs) or portable measurements, there is
no way to connect to an I/O device using OPC. This architecture is also called “pull” technology
because the OPC server always polls the I/O devices from tag creation, IP connection and the tag
status update.
Moxa Active Ethernet I/O – ioLogik series products provide the I/O status report via TCP/UDP
message, e-mail or SNMP traps. These benefits have now expanded to the OPC technology.
Without asking any questions, even the IP address, settings of a tag are automatically created by
the ioLogik itself to notify which tag should be created. Users need only to launch the Active OPC
Server program, and those I/O channels selected by a user will be “pushed” from an ioLogik to
Active OPC Server.