Rockwell Automation 2708-DH5B2L_DH5B4L Attended Workstation - Manual (Page 68)

Chapter 6
Operating Procedures
6–5
When a workstation is first added to the network, it may not immediately be
recognized by the Master. This recognition may take up to a minute. During
this period, when 1–Network Status is entered, a workstation not yet
recognized by the network will display:
nn READY
OFFLINE
As soon as communications are established, the display changes to:
cc–nn READY
ONLINE
If the workstation does not come online in approximately 1 minute, the
cables should be checked. This can be done quickly by substituting a known
working workstation at the questionable position. If the cabling is fine, then
check the site parameter list for this workstation. Verify that the parameters
are set correctly.
Any attempts to load application programs into individual workstations
should not be attempted until the ONLINE message has been received from
that workstation. Premature attempts at downloading a program can result in
nothing being loaded into the workstation.
Visual examinatioin of the 7–Program Load Status display should show
whether a program has been loaded properly.
Network problems usually fall into one of the following categories:
Configuration error This is usually a duplicate station number, but . . . .
can be caused by configuring two Masters and
starting them at the same time.
Cabling error The most common error is caused by switching . . . . . . . . .
polarity of the network wires. Other errors
include: cold solder joints, improper grounding,
excessive induced noise and failure to set the
Terminator switch on one AND ONLY ONE of
a string of workstations.
Workstation malfunction The most likely workstation malfunction which
can effect network operation is a workstation
which contains an improperly operating RS-485
line driver. Such a workstation can render the
entire network inoperable until it is located and
removed.
Adding a Workstation
to the Network
Network Problems