Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 95)

Section 3A
Primary 9/230 Components
3A-12
The Analog Servo control is a function at the 9/230 Analog processor
board. The control calculates positioning and velocity data and processes
the data to generate the necessary analog drive signals. These signals are
sent to the analog servo amplifiers, which power the servo motors of the
machine. The 9/230 Analog may control up to three closed loop axes and
one open loop axis (typically used for a spindle).
The control receives position data from the axis feedback devices. It
combines this position feedback data with the interpolated commands from
the control to generate the command signals that are outputs to the servo
amplifiers.
The function of the control on the processor module is designed to make
the servomotors run with optimum performance. The maximum feedrates
are limited by the mechanical abilities of the machine. System gain and
the maximum allowable following error also limit the feedrates. These
limits are entered as AMP parameters. Refer to the 9/Series CNC 9/230,
9/260, and 9/290 AMP Reference Manual, publication 8520-6.4, for more
information.
Table 3A.E lists the analog servo output specifications. This table is
provided as an aid to determine the compatibility of different analog servo
amplifiers. This section contains a list of compatible analog servos. Input
specifications are discussed in sections covering the individual input
devices. Refer to Table 3A.I for encoder feedback input specifications.
Table 3A.E
Analog Servo Interface Output Specifications
Item Specification Remark
Output Voltage Range ± 10V
Output Offset Voltage 500 m V Max.
Resolution 1.22mV (13 bits) 1
Sampling Frequency 500 Hz
Output Current 5mA Max.
Load Range 2K ohms to infinity
Conversion Time 8.25 m s
Differential
Non-Linearity
± 1 LSB Max. 2
Gain Error ± 1 LSB Max.
Load Capacitance 0.01 m F Max.
1 This resolution is obtained through software. It is equal to a
13-bit numeric value with an additional sign bit (14 bits total).
2 Monotonic over the entire temperature range. LSB means
least significant bit.
3A.2.2
Analog Servo Operation and
Specifications