User manual

116 Publication LOGIX-AP010B-EN-P - May 2010
Chapter 7 Drive and Loop Control
The RSLogix 5000 motion instruction set provides commands for a variety of
operations to control servo drives including the following:
• Change the state of an axis – enabling/disabling an axis or setting the
output voltage to an axis.
• Control the axis position – stopping/jogging an axis or sending an axis to
a home position. Changing the speed, acceleration or deceleration of an
axis.
• Initiate action on all axis – perform certain actions, such as shutdown, on
all axis.
• Tune an axis – calculate the gain and dynamic limits of an axis.
• Control Multi-Axis Coordinated Motion – start a linear/circulate move for
axis of a coordinated system. Calculate the position of one co-coordinated
system with respect to another coordinate system.
Replacing S5 Positioning
Module with Logix
The S5 servomotor control module relies on hard-wired input signals from an
encoder to determine the position of an axis and it outputs a hard-wired
analog ±10V signal to a motor drive to control the motor. An S5 servomotor
control module can control only one motor and can receive only encoder
reference data from one encoder.
In RSLogix 5000 software, commands to the motor and status information
from the motor are all transmitted along a fiber-optic link. This fiber-optic link
can network to multiple drives so that the speed and position of several axis of
movement is easily controlled in a coordinated way.
In upgrading S5 servomotor control to a Logix controlled system, it is likely
that the encoder and drive must be upgraded to an intelligent drive compatible
with the Logix fiber-optic network and its speed and position controlled with a
RSLogix 5000 motion interface modules.
In some applications it may be possible to retain the encoder and wire it to an
Allen Bradley encoder/counter module (model no.1734-IJ or 1734-IK). The
servomotor could then be a controller via an analog output module. However,
this would not give the same degree of accuracy or consistency achieved by
using a Logix SERCOS drive interface module.
Controller with Motion
The 1756-L60M03SE controller combines a 1756-L6x controller and a
SERCOS motion module in a two-slot module. This controller is ideal for
small motion systems and can control three SERCOS axes with the included
interface. This controller can control as many as six axes if you add an
additional motion module,1756-L60M03SE.