User's Manual

COBALT UHF-SERIES CHAPTER 6: ETHERNET/IP INTERFACE
PAGE 97 OF 140
6.7 CHECKING ONDEMAND STATUS
Now that you have configured the Cobalt’s Node and defined corresponding Write
and Read Tags in the PLC, the last step is to check the communication status
between the Cobalt and the PLC.
Return to the Cobalt’s HTML Server - Main Page and click the link labeled
“OnDemand Status.” The OnDemand Status Page will be displayed.
Figure 6-4: The OnDemand Status Page
The OnDemand Status Page provides statistical information regarding the connection
status of the Cobalt. This information can be used to verify that read and write
connections between the Cobalt and the PLC have been established successfully.
 Read Counts: this value indicates the number of times the Cobalt has checked
the PLC for new data.
 Write Counts: this value indicates the number of times the Cobalt has provided
data to the PLC.
Note that under Ethernet/IP, the host (and/or PLC) acts as the server. However,
additional messaging instructions are not required on the part of the host because
the Cobalt will automatically poll the Read Tag in the PLC at the interval specified by
the Read Delay value set via the OnDemand Configuration Utility.
There is no delay parameter when writing data to the PLC, as the Cobalt delivers all
PLC-bound data immediately after it is generated.
If you configured a low Read Delay value, the Read Counts on the OnDemand
Status Page will accumulate rapidly. This occurs because a low Read Delay value
instructs the Cobalt to poll the PLC for new data more frequently.
ATTENTION:
If the Cobalt and PLC do not successfully establish a connection, cycle power to the
Cobalt and verify that Ethernet/IP services are running properly on the PLC. If that does
not resolve the issue, restart Ethernet/IP services on the PLC and the 1756-ENBT
module.