Rockwell Automation 1771-QB Linear Pos. - Manual (Page 114)

Formatting Module Data (WRITES)
Chapter 7
7Ć35
Bit 1 – Hardware Start Enable
Bit 1 in the first axis control word is the hardware start enable bit. Setting this
bit enables the hardware start input. If this bit is reset, the loop ignores hardware
start commands. Note that the discrete inputs must also be enabled by the
parameter block before the module will recognize hardware start inputs.
Hardware start commands aren’t accepted until the loop is in auto mode. If the
start/stop enhancement bit in the parameter block control word is reset, the
hardware start commands are not accepted until the axis in in position. If this bit
is set, the hardware start commands will be accepted during axis motion, just as
software start commands are.
Bit 2 – Auto/Manual
The auto/manual bit selects the mode of operation for the axis:
Off = manual mode
On = auto mode
The module enters manual mode if either the hardware input or the auto/manual
bit go low. If the hardware inputs are disabled (via the parameter block), the
hardware auto/manual input is ignored.
Important: If the mode is changed while the axis is in motion, the status block
indicates a programming error and the axis stops at the current deceleration rate.
The programming error bit clears when the axis motion stops. If the mode
change is still commanded after axis motion stops, the mode will change.
Bit 3 – Incremental Move 13
The incremental move 13 bit determines whether Setpoint 13 (in the command
block) is an incremental or absolute setpoint move:
Off = absolute
On = incremental
See setpoint block, incremental/absolute word for an explanation of incremental
and absolute moves.
Bit 4 – Jog Rate Select
The jog rate select bit determines the rate for jogs:
Off = low jog rate