Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 121)

Chapter
5
Publication 1771-UM002A–EN–P – May 2000
Troubleshooting
A programming error will be reflected in the status word of the
affected axis with the programming error bit set (bit 04). The
systems fault bit in some cases will also be set. When the system
fault bit is not set, programming errors can be cleared by transferring
new error-free block transfer data of any length to that same axis.
When new data or commands are appropriately acted upon by the
stepper controller module, the programming error bit in the status
word will be cleared. A stop or reset command can also be
transferred to the stepper controller module to clear the error.
When a system fault is detected by the stepper controller module
with or without a programming error, the system fault bit (bit 03)
will be set in the status word of the affected axis. When a system
fault is detected, no additional move data will be sent by the stepper
controller module to the pulse output expander module.
Consequently at the end of the current move, the pulse output
expander module would decelerate to 0Hz at the programmed decel
value. A system fault can be cleared by a reset command, only. The
global reset command (MCW, bit 04 = 1, 05 = 1) is a convenient way
to clear all previously loaded data for all axes.
Troubleshooting tables for power-up (Table 5.A) and operation
(Table 5.B) are found at the end of this section. The power-up
troubleshooting table lists combination of LED indicators which will
illuminate due to various faults and errors. Possible causes and
corrective action are also listed. The most probable occurrences are
listed first. The first LED combination listed shows the indicators
when the stepper positioning assembly is operating normally.
The operation troubleshooting table lists possible causes of
programming errors and corresponding corrective action.
Programming errors which do not cause a system fault are listed first
(system fault bit 03 = 0). Programming errors which cause a system
fault (system fault bit 03 = 1) are listed last. The most probable
occurrences are listed ahead of less probable occurrences in both
parts of this table.
General
Troubleshooting Tables