User's Manual

COBALT UHF-SERIES CHAPTER 6: ETHERNET/IP INTERFACE
PAGE 96 OF 140
13.
At the OnDemand Status Page, click the link labeled “
Main Page
” to return to the
HTML Server – Main Page.
6.6 CONFIGURING PLC CONTROLLER TAGS
After you have configured the Cobalt’s Node via the OnDemand Configuration Page,
open your PLC program (i.e. RSLogix 5000) and, if you have not already done so,
define two Controller Tags (a Write Tag and a Read Tag).
Controller Tag Naming
Controller Tags need to be assigned a name and size. Be sure to use the same
Write Tag Name and Read Tag Name that you specified in the OnDemand Node
Configuration (i.e., EMS_WRITE1 and EMS_READ1).
Controller Tag Size
Due to handshaking overhead, Controller Tags must have the size capacity to store
an integer array equal to your previously specified Write/Read Size + three words.
So for example, if the Read Size you specified earlier was 100 words, the
corresponding Read Tag in the PLC must be able to store an array of 103 integers.
 The Write Tag holds messages and response data generated by the Cobalt that
is bound for the host or PLC.
 The Read Tag holds RFID commands and instructions intended for the Cobalt.
(NOTE: the Cobalt should already be linked to the proper Write Tag and Read Tag
via the OnDemand Utilities - OnDemand Configuration Page).
After creating and defining a Write Tag and a Read Tag for the Cobalt, return to the
Cobalt’s HTML Server – Main Page to continue.