Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 45)

3–23 Programming and Operation
Publication 1771-UM002A–EN–P – May 2000
Bit 03 System Fault Bit.
This bit is set if a system failure such as a communication error is
detected in the stepper positioning assembly, or invalid data is
detected. The output decelerates to 0Hz at the programmed decel
value when a system failure is detected.
Bit 04 Programming Error Bit.
This bit will be set for a number of error conditions including the
following.
•
Illegal bit combinations exist in the data transferred to the
stepper controller module. Refer to Table 5.C, Illegal Bit
Combinations, in Chapter 5.
•
The identification bits (bits 16 and 17) of the SMCW are not
set.
•
Any undefined bit is set (other than zero) in the following
words:
– MS Preset (bits 14-16)
– LS Preset (bits 14-17)
– Ramp (bits 14-17)
– Decel (bits 14-17)
– MS Position (bits 14-17)
– LS Position (bits 14-17)
•
Rate values exceed 20,000 pulses per second.
•
Ramp or decel values exceed 9.99 seconds.
•
Preset or position values exceed 999,999 pulses.
Important: The stepper controller module checks these conditions
when data is first received. At a later time when a
move is being processed for execution, other invalid
data can be detected. Invalid data (such as that which
would cause the final rate of a move to be held for less
than 20ms) will cause both a programming error (bit
04) and a system fault (bit 03). The positioning profile
would then cease.
Bit 05 Reset Bit.
This bit is set when a reset command is received and at power-up.
Anytime a reset command is received, the done bit and reset bit will
be on. Both bits are reset when the first move of the next moveset
begins.
Bit 06 Software Stop Bit.
This bit is set when a software stop command is received.
Bit 07 Hardware Stop Bit.
This bit is set when a hardware stop (E-STOP) command is received.