Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 724)

Section 15A
Troubleshooting The Control
15A-14
Displayed to the right of the device is the device number. Assigning
device numbers is explained starting on page 10A-1. Different types of
I/O devices can have the same device number, however, when more than
one of the same type of device is resident on the I/O Ring, each one must
have a unique device number.
A device can be selected for diagnostic viewing by using the up or down
cursor keys on the operator panel keyboard. If the cursor down key is
pressed while the cursor is on the bottom line, the next page of devices is
displayed (if more devices exist).
Pressing the {DISPLY} softkey after the desired device has been selected,
will result in an I/O status screen being displayed, which may be used to
monitor the selected device.
The {RECVRY --DISABLE} and {RECVRY --ENABLE} softkeys
determine how the I/O ring will operate if the data integrity checks indicate
a bad set of data from the ring.
{RECVRY --ENABLE} : This is the Power Turn On mode. When
active, the control will try to RECOVER by re--sending / re--reading the
ring data. If the remains for a fixed number of retrys, an E--STOP is
generated. After the E--stop is generated the control CONTINUES to
re--try. This may result in the ring recovering after the E--stop and error
message are generated. While this fault tolerent operation is normally
good, it makes trouble shooting of an intermittent I/O ring difficult.
{RECVRY --DISABLE} : This mode of ring operation can be selected
for diagnostic purposes. When active, the control will not try to recover
when a fault in the I/O ring data integrity is detected. It will
immediately cause an E--STOP and do no retrys of the ring data. This
allows the faulty Ring device to be more easily identified.
If a Digital I/O device is selected on the Ring I/O screen and the
{DISPLY} softkey is pressed, the Digital I/O Diagnostics screen appears.
Figure 15A.2 is an example of this screen.
15A.4.1
Digital I/O