Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 78)

Programming
Chapter 3
3Ć35
the error, W01 B07 must be set to 1 so that the loop time/diagnostic
word W60 can report diagnostic information. The lower byte of
W60 will contain the error code. See word W60 below for additional
information.
W58 B13 Power-Up. After the PID module has received the first
valid dynamic block with the load bit W01 B06 =1, this bit will be
reset to 0. Note that this does not mean that the PID module is
programmed, only that the first dynamic block has been processed.
After the PID module has gone through its initial power-up
procedure or after the restoration of +5VDC, it will set bit W58 B13
to 1. This occurs when the module has cleared all internal memory
and is waiting to be programmed by block transfers to complete the
initial load/enter sequence. See section titled Power-Up Load/Enter
Sequence for additional power-up load/enter sequence information.
W58 B12 Ready. Set to 1 indicates that the load portion of the
load/enter sequence has been successfully completed. The ready bit
should be used to initiate the setting of the enter bit to complete the
sequence. After the enter bit is received by the PID module, the
ready bit will be reset to 0.
Before the enter bit is received by the PID module, a ready bit status
of 0 indicates an error was detected in either the dynamic block or a
loop block during the load portion of the load/enter sequence. The
error must be corrected before the ready bit can be set to 1. See
section titled Load/Enter Sequence or additional Load/enter sequence
information.