Accessory 24E2
INTRODUCTION
Overview
The ACC-24E2 Axis Expansion Board provides two or four channels of PMAC2-style direct PWM servo
interface circuitry for UMAC and Ultralite/MACRO Station controllers. The ACC-24E2 is part of the
UMAC family of expansion cards and these accessory cards are designed to plug into an industrial 3U
rack system. The information from these accessories is passed directly to either the UMAC or MACRO
Station CPU via the high speed UBUS expansion bus. Other axis or feedback interface UBUS
accessories include the following:
ACC-14E
Parallel Feedback Inputs (absolute enc. or interferometers)
ACC-24E2
Digital Amplifier Breakout w/ TTL encoder inputs
ACC-24E2A
Analog Amplifier Breakout w/ TTL encoder inputs
ACC-24E2S
Stepper Amplifier Breakout w/ TTL encoder inputs
ACC-28E
16-bit A/D Converter Inputs (up to four per card)
ACC-51E
4096 times interpolator for 1Vpp sinusoidal encoders
ACC-53E
SSI encoder interface (up to 8 channels)
Up to eight ACC-24E2x boards can be connected to one UMAC providing up to 32 additional channels of
servo interface circuitry. Because each MACRO Station CPU can service only eight channels of servo
data, only two ACC24E2x boards can be connected to the MACRO-Station. The new MACRO 16-Axis
CPU can support four ACC-24E2x cards.
The ACC-24E2 board contains no processor; it has one highly integrated 4-channel PMAC2-style Servo
IC with the buffering circuitry and connectors around them. The two-axis ACC-24E2 plugs into the
backplane and uses one slot in the Rack. If two more axes are needed, ACC-24E2 Option 1 can be
plugged into the ACC-24E2 connectors. The ACC-24E2 with its Option 1 card takes up a total of two
slots.
Features
The ACC-24E2 board can be used with any UMAC or MACRO Station CPU, interfacing through the
UBUS.
The ACC-24E2 supports both Direct PWM servo and PFM stepper interfaces:
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Direct digital pulse-width modulated (PWM) phase voltage commands
Pulse-and-direction commands
Board Configuration
An ACC-24E2 comes standard with one Servo IC providing four servo interface channels, which are
brought out on terminal blocks and mini D-Sub connectors. Two of these channels are brought out on the
single-board base configuration.
Each channel of servo interface circuitry includes the following:
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Two output command signal sets, configurable as either:
One pulse-and-direction
Three PWM top-and-bottom pairs
AB-Quadrature and Index pulse differential/single-ended encoder input
Nine input flags, two output flags
Interface to two external serial ADCs, 8 to 18 bits, for current loop feedback
Introduction
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