Rockwell Automation 1771-QB Linear Pos. - Manual (Page 66)

Interpreting ModuleĆtoĆPLC Data
(READS)
Chapter 6
6Ć5
Bit 4 – Auto Mode
The auto mode bit turns on when the loop is in auto mode, i.e., when the
auto/manual bit in the command block is on and the auto/manual hardware
input is true. The auto/manual hardware input is true if the module is receiving a
high input at the AUTO/MAN discrete input terminal (13/14) or if the discrete
inputs are disabled in the parameter block.
Don’t confuse the auto mode bit with the auto/manual bit (bit 9). The
auto/manual bit simply reflects the state of the signal at the AUTO/MAN
discrete input terminal (13/14), regardless of whether or not the discrete inputs
are disabled.
Bit 5 – Programming Error
If the module detects an illegal bit combination, such as a non-BCD value
where it expects a BCD value, it turns on the programming error bit. You can
get additional information from words 4, 5 and 8, 9 if they are configured to
display diagnostics. The programming error bit clears when the error condition
ends.
Bit 6 – PID Active
The PID bit is on when the integral and derivative terms are enabled. It turns off
during axis movement in response to a setpoint or jog command.
Bit 7 – Block Transfer Write Toggle
When the module receives and successfully decodes a block transfer whose
block contents or size differ from the previous valid block transfer received, the
block transfer write bit is toggled. As long as no programming error occurs, any
valid block transfer received by the module will toggle this bit. This lets you
synchronize block transfers and ensure that every block transfer sent to the
module has been received.
Bit 8 – Inputs Enabled
The inputs enabled bit is off after powerup or after a reset command. It turns on
if you enable the discrete inputs by the parameter block. If the discrete inputs
are disabled, their status is still displayed in bits 9 through 15 of this status
word, but their functions are disabled.
Bit 9 – Auto/Manual
The auto/manual bit reflects the state of the auto/manual hardware input
(0 = manual mode, 1 = auto mode).