Celerity ACX3200 Series User manual

ACX3200/ACX3400 Series
Adaptive Pressure Controllers
User Guide
Celerity, Inc.
915 Enterprise Boulevard
Allen, TX 75013 USA
T [phone]
F [phone]
SD536577 REV 001 08/07

p.i
SAFETY NOTICES 1
_0.1 SAFETY SYMBOLS 1
_0.2 GROUNDING 1
_0.3 EXPLOSIVE ATMOSPHERE 1
_0.4 PART SUBSTITUTIONS AND MODIFICATIONS 1
_0.5 GENERAL SAFETY GUIDELINES 1
_0.5.1 Unsafe Acts 2
_0.5.2 Recommended practices 2
_1.0 INTRODUCTION 3
_2.0 DESCRIPTION 4
_2.1 SYSTEM OVERVIEW 4
_2.2 ACX FEATURES 4
_2.3 CONTROLLING THE SYSTEM PRESSURE 5
_2.4 ADAPTIVE PRESSURE CONTROL 5
_2.5 PID PRESSURE CONTROL 6
_2.6 PID TUNING 6
_2.7 HYBRID ALGORITHM 7
_2.8 VALVE POSITIONING 7
_2.9 MANUAL VALVE OVERRIDE 7
_3.0 INSTALLATION 9
_3.1 MOUNTING - ACX3200 AND ACX3400. 9
_4.0 CONFIGURATION 10
_4.1 RS-232 INTERFACE 10
_4.2 RS-232C DCE DESCRIPTION 10
_4.3 HARDWARE HANDSHAKING 12
_4.4 RS-422 INTERFACE 13
_4.5 RS-485 INTERFACE 13
_4.6 SELECTING NUMBER OF CM INPUTS 14
_4.7 SELECTING INPUT AND OUTPUT VOLTAGE LEVELS 14
_4.8 FACTORY DEFAULT SWITCH POSITIONS 15
_4.9 OTHER INTERNAL CONFIGURATION SETTINGS 15
_4.9.1 RS-232 and RS-485 Communication 15
_4.9.2 Other Internal Connectors and Jumpers 16
_4.10 INTERFACING TO ACX REAR PANEL 16
_4.10.1 ACX3200 and ACX3400 Power Input 16
_CONTENTS

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_4.10.2 Device Port 16
_4.10.3 CM1 and CM2 Interfacing 17
_4.10.4 Throttle Valve 18
_4.10.5 Auxiliary Port 18
_4.10.6 Serial Interface Port 18
_5.0 LOCAL OPERATION 19
_5.1 ACX3400 FRONT PANEL KEYPAD OPERATION 19
_5.2 ACX3400 FRONT PANEL MENU FUNCTIONS 19
_5.2.1 Setpoints 19
_5.2.2 PID Gain 19
_5.2.3 PID Phase 20
_5.2.4 Trip Point 1 20
_5.2.5 Trip Point 2 20
_5.2.6 Sensor Range 20
_5.2.7 Lock High Sensor 20
_5.2.8 Release Sensor Lock 20
_5.2.9 Set Valve Angle 20
_5.2.10 Algorithm Select 21
_5.2.11 Units Select 21
_5.2.12 Software Version, Serial Port Configuration, Analog
Output Voltage Range 21
_5.2.13 Change Zero Offset 21
_5.2.14 Reset Zero 21
_5.2.15 Zero offset 21
_6.0 SERIAL INTERFACE 22
_6.1 INTRODUCTION 22
_6.1.1 Command Notation 22
_6.1.2 Command Strings 22
_6.2 COMMAND OVERVIEW 23
_7.0 FUNCTIONAL CONTROL COMMANDS 24
_7.1 SET PRESSURE CONTROL ALGORITHM 25
_7.2 SET PID ALGORITHM 25
_7.3 LEARN ALGORITHM 26
_7.4 OPEN VALVE COMMAND 26
_7.5 CLOSE VALVE COMMAND 26
_7.6 HOLD VALVE COMMAND 26
_7.7 GO TO VALVE ANGLE COMMAND 27
_7.8 ADJUST PRESSURE COMMAND (ZERO ADJUST) 27
_7.9 REMOVE ZERO OFFSET 27
_7.10 ZERO THE SENSOR 28
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_7.11 SET NUMBER OF CMS 28
_7.12 SET CM FULL SCALE 28
_7.13 CM SELECT 28
_7.14 ECHO SOFTWARE SWITCH 29
_7.15 HARDWARE HANDSHAKING 29
_7.16 INITIALIZE ACX 30
_7.17 LOCK TO HIGH SENSOR 30
_7.18 LOCK TO LOW SENSOR 30
_7.19 RELEASE SENSOR LOCK 30
_7.20 SETPOINT COMMAND 30
_7.21 CONTROL TO SETPOINT 31
_7.22 SET GAIN 32
_7.23 SET GAIN COMPENSATION FACTOR 32
_7.24 SET PHASE 33
_7.25 SET PHASE COMPENSATION FACTOR 34
_7.26 SET TRIP POINT 34
_8.0 RAMP FUNCTION COMMANDS 36
_8.1 RAMP FUNCTION BEHAVIOR 36
_8.2 SET RAMP FUNCTION 37
_8.3 SET PRIMARY RAMP SETPOINT 38
_8.4 SET PRIMARY SETPOINT DELAY TIME 38
_8.5 SET SECONDARY RAMP SETPOINT 38
_8.6 SET SECONDARY SETPOINT RAMP TIME 38
_8.7 SET SECONDARY RAMP SETPOINT DELTA TIME 38
_9.0 REPORT (STATUS) COMMANDS 39
_9.1 INITIATE DIAGNOSTIC ROUTINE 40
_9.2 REPORT ALGORITHM TYPE 40
_9.3 REPORT CM RANGE 40
_9.4 REPORT COMMAND 40
_9.5 REPORT DIAGNOSTIC STATUS WORD 41
_9.6 REPORT GAIN 42
_9.7 REPORT GAIN COMPENSATION FACTOR 43
_9.8 REPORT MODEL ID 43
_9.9 REPORT OPERATIONAL STATUS WORD 43
_9.10 REPORT PHASE 45
_

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_9.11 REPORT PHASE COMPENSATION FACTOR 46
_9.12 REPORT PRIMARY RAMP SETPOINT 46
_9.13 REPORT PRIMARY SETPOINT DELAY TIME 46
_9.14 REPORT RAMP FUNCTION STATUS 46
_9.15 REPORT SECONDARY RAMP SETPOINT 46
_9.16 REPORT SECONDARY SETPOINT DELTA TIME 47
_9.17 REPORT SECONDARY SETPOINT RAMP TIME 47
_9.18 REPORT SETPOINT 47
_9.19 REPORT SOFTWARE ID 47
_9.20 REPORT SYSTEM PRESSURE 48
_9.21 REPORT TRIP POINT 48
_9.22 REPORT VALVE ANGLE 48
_9.23 REPORT VENDOR ID 49
_9.24 HELP SCREEN 49
_10.0 RS-485 SERIAL INPUT/OUTPUT 50
_10.1 THEORY OF OPERATION 50
_10.2 UNIQUE DEVICE ADDRESS 50
_10.3 RS-485 DATA LINK 50
_10.4 MODIFYING THE RS-485 ADDRESS 51
_10.5 GENERAL OPERATION 51
_10.6 COMMAND RESPONSE AND ACKNOWLEDGEMENT 51
_11.0 AUXILIARY INTERFACE 54
_11.1 AUXILIARY PORT FUNCTIONS 56
_11.1.1 Trip Point Relays 56
_11.2 CONTROL INPUTS 57
_11.2.1 Hold/Control Select 57
_11.2.2 Close Input 57
_11.2.3 Open Input 57
_11.2.4 Remote Zero 57
_11.2.5 Pressure/Valve Input Select 58
_11.2.6 CM Select 58
_11.2.7 Digital Ground 58
_11.3 STATUS OUTPUTS 58
_11.3.1 Valve Open Status 58
_11.3.2 Valve Closed Status 58
_11.3.3 Valve Status Output Common 58
_11.3.4 CM Out 59
_11.4 ANALOG SIGNALS 59
_11.4.1 Analog Ground 59
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_11.4.2 Analog Setpoint/Valve Angle Input 59
_11.4.3 Pressure Signal Output 59
_11.4.4 Valve Angle Signal Output 59
_12.0 MAINTENANCE AND TROUBLESHOOTING 61
_12.1 CLEANING AND ROUTINE MAINTENANCE 61
_12.2 TROUBLESHOOTING GUIDE 61
_12.3 ACX3400 ERROR MESSAGES 61
_13.0 ASCII CHARACTER CODES 62
_14.0 SERIAL PORT ADAPTORS 63
_15.0 WARRANTY 64
_

p.1
0.0 SAFETY NOTICES
This manual provides information for the installation and operation of the Celer-
ity ACX3200 and ACX3400 Series Downstream Pressure Controllers. It is
imperative that this manual be reviewed prior to installation and operation of the
device. Failure to comply with the warnings, cautions, and hazard notes will void
the product’s warranty. Use of these instruments in a manner other than those
specified by Celerity may result in injury or death and will void the product’s war-
ranty. Celerity assumes no liability for any damage resulting from the improper
use of its products.
0.1 SAFETY SYMBOLS
The following safety symbols are used throughout the system documentation:
CAUTION !!
Damage to equipment or software could result if stated or local procedures are not
followed.
WARNING
!!
Injury to user or other personnel could result if stated or local procedures are not
followed.
DANGER
Severe injury or injury resulting in death could result if stated or local procedures
are not followed.
0.2 GROUNDING
All devices must be properly grounded to reduce the risk of an electrical shock.
0.3 EXPLOSIVE ATMOSPHERE
The ACX family of products are NOT intended for use in explosive atmospheres.
0.4 PART SUBSTITUTIONS AND MODIFICATIONS
Modifying an instrument in any way not only voids the warranty but could cause
a safety hazard and should be avoided. Repair work should be done at the fac-
tory or by a factory-authorized service center.
0.5 GENERAL SAFETY GUIDELINES
Always follow established industrial safety practices when operating any produc-
tion equipment.
Safety is designed into every product. When followed, these minimum guide-
lines provide an acceptable level of safety for operating and maintaining your
system. They are not, however, a substitute for determining your own internal
safety procedures.
Use of controls, adjustments, or procedures other than those specified in this
manual without consulting a competent safety professional may result in expo-
sure to potential hazards. Always follow established industrial safety practices
when operating production equipment.
DANGER
SHOCK HAZARD. All devices
must be properly grounded to
reduce the risk of electrical
shock. The 3-conductor power
cord supplied the AXC3200
and ACX3400 pressure
controllers provides the
required grounding when
connected to a properly
grounded main circuit. See
Figure 9, Rear Panels, on
Page 16 for further details.
DANGER
Do not use equipment in an
explosive atmosphere. The
ACX family of products are
NOT intended for use in
explosive atmospheres.
CAUTION !!
Do not substitute parts or
modify equipment.
0.0
_SAFETY
AXC3200

p.2
0.5.1 Unsafe Acts
• NEVER defeat a safety interlock unless you are certified to perform the proce-
dure and have been specifically directed to defeat the interlock.
• NEVER operate or service this system without a thorough knowledge of the
dangers involved and the precautions to be followed for safe and efficient
operation.
• NEVER disregard instructions to lockout/tagout the system.
• NEVER permit unauthorized or untrained personnel to use the system.
• NEVER STAND IN WATER OR ON A WET SURFACE WHILE OPERATING
ANY ELECTRICALLY POWERED EQUIPMENT.
• NEVER place your hands near moving parts or energized parts or sub-
systems. Components can move rapidly.
• NEVER remove a warning label from the equipment.
• NEVER operate damaged equipment.
• NEVER permit unauthorized or untrained personnel access to the system.
0.5.2 Recommended practices
• USE THE BUDDY SYSTEM: ALWAYS perform maintenance procedures in
teams of two or more people; one to monitor the controls and indicators, and
one to watch the system operation.
• ALWAYS observe all warning labels.
• ALWAYS avoid all unsafe acts.
The safety procedures described in this manual are minimum guidelines. It is
believed that these guidelines will provide an acceptable level of safety. These
guidelines, however, should not be considered a substitute for determining your
own internal safety procedures in consultation with a competent safety profes-
sional.
DANGER
Use of controls, adjustments,
or procedures other than those
specified in this manual
without consulting a
competent safety professional
may result in exposure to
potential hazards
_

p.3
1.0 INTRODUCTION
This manual provides the necessary information to configure, install andoperate
ACX Downstream Pressure Controllers. These include:
The Installation section presents the information on physical dimensions,
mounting considerations, performance and electrical specifications, power sup-
ply requirements and interfacing pinout tables for connecting devices to the
ACX. Serial port interfacing and configuration of externally selectable dip
switches are also included.
The Operation section describes the options for interfacing to the ACX. The
Serial port and Auxiliary port considerations, advantages and limitations are dis-
cussed. The ACX provides multiple control algorithms for controlling pressure.
The uses of each are described along with sensor input configurations, valve
positioning and control options.
The Auxiliary Interface section describes in detail the requirements for electri-
cally controlling and monitoring the ACX using contact closure and analog sig-
nals.
All commands and functions of the ACX may be performed using the RS-232 or
RS-485 communications port. The Serial Interface and RS-485 Serial Input/Out-
put sections provide syntax and descriptions of the available commands.
The Appendices provide information on the ASCII character set for use with the
serial port. Also shown is wiring information for using the RS-232 adaptor for 9
and 25 pin “D” type connectors to RJ-12 type connectors.
Model Communication Additional Features
RS-232 RS-485
ACX3201 √auxiliary port
AC powered
ACX3211 √
ACX3401 √auxiliary port front panel
AC powered
ACX3411 √
1.0
_INTRODUCTION

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2.0 DESCRIPTION
2.1 SYSTEM OVERVIEW
The ACX provides precision control of process chamber pressures through a
closed-loop systems approach: pressure control is achieved by controlling the
rotation of a specially designed throttle plate in the exhaust line. One or more
capacitance manometers (CMs) provide pressure feedback. A typical system
block diagram is shown below.
Figure 1: System Block Diagram
The ACX is available in two basic configurations:
• with front panel rack mount
• with a display/control panel
The ACX3200 Series includes a contact closure and analog input/output signal
interface and a full-featured communications port.
The ACX3400 Series provides the same features as the ACX3200 Series and
includes a front-panel keypad and display for full system control and monitoring.
The ACX3200 and ACX3400 are configured with internal AC-operated power
supplies. See Table 1 on page 8 for details.
2.2 ACX FEATURES
• User-selectable pressure control algorithms.
Adaptive control - no phase lead or gain adjustments are necessary. The sys-
tem automatically adapts to changes in operating parameters in real time.
Proportional Integral Differential (PID) algorithm.
Learning algorithm automatically selects PID parameters.
Hybrid algorithm using both PID and Adaptive features.
• The ACX can monitor two CMs with complementary ranges to extend the con-
trol range up to 5 decades of pressure.
Exhaust
MDVX
Gas
Flow
CM(s)
Process
Chamber
Pressure Controller
RS-232 (RS-485)
control from system
controller
TTL/Analog
control system
controller
2.0
_DESCRIPTION

p.5
• The Serial Port interface allows for monitoring and control using standard
ASCII character formats.
• Valve angle control - the throttle valve can be positioned to any valve angle to
within less than 0.1 degrees.
• The Auxiliary port allows remote contact closure to control major functions. It
provides valve status indications, a 0-5 or 0-10 VDC analog setpoint input, 0-
5 or 0-10 VDC pressure and valve angle output and two adjustable Trip Point
relays.
• Remote pressure adjustment (zeroing) - the pressure signal can be zeroed
remotely without adjusting the zero potentiometer at the CM.*
• May be used to retrofit existing controllers.
• [ACX3200 models only] Manual Valve override - a rear panel toggle switch
allows the user to override control and drive the valve to the open or closed
position.
• Non-volatile memory retains configuration parameters in the event of loss of
power.
• [ACX3400 models only] Keypad and display for local operation.
*Consult with factory on configurations.
2.3 Controlling the System Pressure
• The ACX provides the ability to control pressure using a patented Adaptive
Control Algorithm (U.S. Patent No. 4,720,807) or an industry-recognized PID
type algorithm. The Adaptive algorithm is based on existing, proven
technology and provides a superior level of pressure control without tuning or
learning routines. A PID algorithm allows the user to manually select phase
and gain parameters to precisely tune the control actions of the ACX. The PID
parameters may be manually selected by the user or automatically selected
using a PID learning algorithm. (Manual fine-tuning of PID parameters may be
needed following completion of the Learn Algorithm.) The Hybrid algorithm
begins pressure control with the PID algorithm using phase and gain
parameters; once settled at setpoint it then uses the Adaptive algorithm for
improved pressure control.
2.4 Adaptive Pressure Control
Adaptive pressure control technology was pioneered by Vacuum General
(Patent now with Celerity, Inc.) in the mid-1980’s when a patent was granted for
the algorithm in the AC-2 Adaptive Pressure Controller. Since that time, adaptive
control technology has been further developed and refined to the point where
the ACX is capable of significant performance improvements over the original
design. The nature of adaptive control requires adequate processing capability
using digital sampling and a closed-loop control algorithm. Wide sample base
determinations can be calculated. Vacuum system variables and transfer func-
tions are then used to regulate algorithm performance. These determinations
can be made an order of magnitude faster than the typical vacuum system
response time and can therefore be assumed to be made in real time.
The ability to achieve adaptive control provides the user with fast, precise pres-
sure control for a wide range of system time constants and transfer functions.
Response tuning is never necessary as the adaptive algorithm calculates and
corrects for all system variables in real time. This means variables such as mass
2.0
_DESCRIPTION

p.6
flow input, pressure set points, etc. can be varied during a process run and the
ACX will instantly adapt to provide optimal control performance.
The adaptive algorithm is available using the serial and auxiliary port interfaces.
In serial mode it is selected by using the “Control to Setpoint using Adaptive”
algorithm command. When using the auxiliary port, the adaptive control algo-
rithm is the only algorithm available and is automatically selected when activat-
ing the control logic pin on the auxiliary port.
2.5 PID Pressure Control
There are circumstances where the system time constants exceed the ability of
the ACX to adequately control pressure using the Adaptive algorithm. An exam-
ple is when the chamber volume is very large and the pumping speed very low.
In this situation there will be a substantial response lag in the system because of
the pump’s inability to quickly pump down the chamber. This response lag may
also be affected by the gas flow rate into the system. For this type of slow
response, the PID algorithm may be selected to manually tune the system for
best performance. This process requires selecting two control loop parameters
which tune the algorithm - phase and gain.
Phase is used to accommodate for the vacuum system’s response time lag by
synchronizing the control algorithm response with the system response. This
synchronization allows the algorithm to position the valve to cause pressure
changes which correspond to the system response lag.
Gain is the speed with which the algorithm creates changes in pressure and is
directly associated with the rate of rise in the system and the effective pumping
speed. The gain is adjusted in conjunction with the phase to tune the response
of the controller to provide the desired time to setpoint and control performance
at setpoint.
Each of the 10 programmable setpoints (serial only) and the analog setpoint
have associated phase and gain values which may be set by the user. When the
“Control to setpoint using PID” command is given, the corresponding phase and
gain values are used by the algorithm. These values may be changed prior to
control or while the PID algorithm is controlling pressure.
2.6 PID Tuning
There are essentially two main objectives when tuning the PID algorithm; how
quickly to achieve setpoint and how tightly to control when setpoint is achieved.
Typically the speed of achieving setpoint can be controlled using gain. The
greater the gain value (0-99) the faster the valve will respond to create a pres-
sure change. The gain also affects the control action of the algorithm when con-
trolling at the setpoint. There is a balance between ramping to setpoint and
controlling at setpoint. Too much gain and the algorithm will achieve setpoint
quickly and then potentially overshoot (and undershoot) while attempting to con-
trol. Reducing the gain will reduce the overshoot.
Tuning the PID algorithm is an interactive process requiring several cycles from
base pressure to setpoint. Once tuned, each setpoint will continue to respond
repeatedly with the selected phase and gain values. If system parameters such
as the gas flow rate, setpoint pressure, system time constants, or pumping
speed are changed, re-tuning the PID algorithm may be required.
2.0
_DESCRIPTION

p.7
2.7 Hybrid Algorithm
To increase the range of pressure control using a PID type algorithm, the Hybrid
Algorithm may be used over a wider range of pressure setpoint and flow rates.
PID is typically set for a specific pressure setpoint and flow rate. With the Hybrid
Algorithm, an interactive test to select the highest gain and adequate phase for
the highest and lowest pressure and flow is needed. Begin with the lowest flow
and pressure. Adjust the gain and phase (refer to the Serial Interface section,
page 22) for optimum performance. Repeat this process for the highest flow and
pressure setpoints. Once the optimum parameters are found, use the highest
gain and “mid-range” phase parameters. Test the lowest setpoint and flow, then
test the highest setpoint and flow. The phase may need to be increased or
decreased slightly. After two or three attempts at the extremes of pressure and
flow, the phase and gain will be properly set. The Hybrid Algorithm will then con-
trol pressure over a wider range than the PID algorithm.
2.8 Valve Positioning
In addition to providing automatic pressure control, the ACX may be used to pre-
cisely position the attached throttle valve. The valve may be set to any position
between fully closed (0°) and fully open (90°). Valve positioning is available
using the serial or auxiliary port interface. In the serial mode the “Go to valve
position” command may be used; when using the auxiliary interface, an analog
signal of 0-5 VDC or 0-10 VDC (user selectable) is used in conjunction with a
contact closure control signal.
2.9 Manual Valve Override
A Manual Valve Override toggle switch is provided to override the ACX software
and position the valve in either the open or closed position. The switch is located
on the rear panel for the ACX3200 models, and on the front panel for the
ACX3400 models.
When the switch is positioned in either the open or close position, the ACX will
drive the valve to the open or closed position. The corresponding valve-position
LED will illuminate when the valve has opened or closed.
Note: This switch will override any command issued to the ACX from either the
serial or auxiliary ports. The valve will remain in the selected open or closed
position until the toggle is returned to the center position and either another
valve position command is issued or, with the ACX3400 models, another button
is pushed.
2.0
_DESCRIPTION

p.8
Table 1: Specifications
1. These power ratings include the motor drive requirements for the
MDV or MDVX and ±15VDC at 1.5 Amps for two heated CMs.
Control Algorithms Advanced Adaptive, Programmable PID,
Learning PID and Hybrid
Control Range 3 to 5 decades of pressure
Control Accuracy 0.25% of reading +0.01% of full scale
Maximum Resolution 0.01% of full scale
Recommended Minimum Setpoint 1.0% of full scale of low range CM
Input Power Requirements190 VAC - 264 VAC @ 50/60Hz 2A
maximum
Input Protection (ACX3200, ACX 3400) 2 AMP circuit breaker
Communications Interface ACX3201, ACX3401: RS-232
ACX3211, ACX3411: RS-485
Pressure Signal Inputs 0-10 VDC linearly proportional to
pressure
Pressure /Valve Angle Output 0-5 VDC or 0-10 VDC user selectable
and linearly proportional
Analog Setpoint Input 0-5 VDC or 0-10 VDC user selectable
and linearly proportional
Valve Open/Close Time < 2 Seconds
Relay Contacts (2) Switch Rating 30 VDC @ 1A maximum, resistive load
Compatible Sensors All of Celerity’s CMs All other sensors with 0-10 VDC linear
output and ±15 VDC input requirements
Compatible valves All of Celerity’s MDV and MDVX
Weight ACX3200 - 3.4 lb [1.55 kg] ACX3400 -
4.4 lb [2.0 kg]
Altitude to 6,000 feet
Operating Temperature Range 0-40°C (Storage temperature of 0-60°C)
Humidity 20 - 90% non-condensing
Environment indoor use
Installation Category II
Pollution Degree 2
20.
_DESCRIPTION

p.9
3.0 INSTALLATION
3.1 MOUNTING - ACX3200 and ACX3400.
Four mounting holes through the front panel provide all necessary mounting
requirements for the ACX3200 and ACX3400:
Figure 2: ACX3200 and ACX 3400 Series Outline Drawing
CAUTION !!
When mounting the ACX3200
and ACX3400 series, be sure
to provide clearance around
the unit for free circulation of
air.
CAUTION !!
Disconnectingthepower cord
is the only way to remove
power from the ACX3200 and
ACX3400 series. When
mounting, be sure to provide
adequate clearance to allow
disconnecting the power
cord.
88.9 mm
[3.50”]
65.0 mm
[2.56”]
309.63 mm
[12.19”]
3.30 mm
[0.13”] 9.65 mm
[0.38”]
ACX3200
42.55 mm
[1.675”] 86.36 mm
[3.40”] 4.75 mm
[0 .187”]
AUXILIAR Y PORT
STATUS
COMM VALVE OVERRIDE
VALVE
~
50 - 60HZ 2A MAX
100V - 240V
PWR INPUT
CB1
S
P
H
U
2
DEVICE PORT
79.38 mm
[3.125”]
171.45 mm
[6.75”]
166.37 mm
[6.55”]
SIDE VIEW
REAR VIEW
FRONT
166.37 mm
[6.55”]
65.0 mm
[2.56”]
3.30 mm
[0.13”]
88.9mm
[3.50”]
9.65 mm
[0.38”]
309.63 mm
[12.19”]
42.55 mm
[1.675”] 86.36 mm
[3.40”]
171.45 mm
[6.75”]
4.75 mm
[0.187”]
79.38 mm
[3.125”]
3.0
_INSTALLATION

p.10
4.0 CONFIGURATION
4.1 RS-232 Interface
The RS-232 port, used on all ACXxx01 models, is the primary interface for con-
trolling the ACX. This port may be configured to accommodate a variety of sys-
tems.
DIP switch S1 (Figure 3) sets the baud rate, stop bits, and parity for the ACX.
The factory settings are baud rate of 9600, 1 stop bit, and no parity (see Figure
4:, Typical DIP Switch S1 Positions, RS-232). Character length is not user con-
figurable and is fixed at 8 bits. Stop bits are only selectable with parity disabled.
If parity is enabled only one stop bit is used.
Access to DIP switches S1 and S2 on the ACX3200 and ACX3400 is provided
by removing the chassis top cover
Figure 3: DIP Switch S1 and S2 Location
Figure 4: Typical DIP Switch S1 Positions, RS-232
4.2 RS-232C DCE Description
The ACX is an RS-232C DCE device. Transmitted data (source: HOST) is an
input to the ACX and is connected to pin 3 of the RS-232 Communications port
(9-pin D-Subminiature connector). Received data (source: ACX) is an output
from the ACX and is connected to pin 2 of the DB9.
The RTS hardware handshaking input (source: HOST) is connected to pin 7 of
the DB9. If the ACX has been configured for hardware handshaking (see the JC
command), this pin is monitored by the ACX software. While this signal is idle
(high state) the ACX transmits requested data. When the input signal is active
(low state) the ACX stops transmitting requested data until the RTS line is raised
once again by the HOST. This control signal has no effect on the ACX if the ACX
is not configured for hardware handshaking.
The CTS hardware handshaking output (source: ACX) is connected to pin 8 of
the DB9. If the ACX has been configured for hardware handshaking, this pin is
controlled by the ACX software. While this signal is idle (high state) the ACX is
S1 S2
REARFRONT
4.0
_CONFIGURATION

p.11
ready to receive data from the HOST. When the output signal is active (low
state) the ACX can no longer accept data from the HOST. The HOST should
stop transmitting data at once.
The ACX can be affected by the absence of the CTS output. Should the ACX
receive input buffer become full, the ACX has no other method to tell the HOST
to stop transmitting data. This is not likely to happen, as the ACX has a large
input buffer.
Pin 6 of the DB9 connector is a Data Set Ready output. This is a +15V output
tied to a pull up resistor. This output is not controlled by either the ACX or the
HOST. This connection is sometimes used by the HOST to verify, without actual
communications, that a device is connected to its serial line. It is not necessary
to use this output signal.
Chassis Ground has two connections on the DB9 connector. Both pin 9 and the
case (shell) are at chassis ground. Do not attach chassis ground from end to end
on either the cable or the case. Use chassis ground only as a cable shield. The
ACX derives chassis ground from the integrated power supply and 3-pin power
cable. Unwanted ground loops could occur if chassis ground is carried through
the RS-232 cable.
Table 2: Typical RS-232 DTE to DCE DB9 Configuration
Note: All signal names reference the HOST as DTE.
When the ACX operates in the RS-232 “three wire” mode, only three lines on the
RS-232 connector are used: the receive and transmit data lines and the ground
pin. In this configuration, the ACX will receive and transmit data as quickly as
possible.
When using the “five-wire” mode, or hardware handshaking, the system control-
ler must support the Request-to-Sent (RTS) and Clear-to-Send (CTS) control
lines. The ACX does not require re-configuration in this mode. The system con-
troller holds the RTS linelow to halt communications from the ACX. Similarly, the
ACX holds the CTS line low when the ACX is not ready to accept communica-
tions from the system controller. Refer to the Serial Interface section for details
regarding activating the hardware handshaking (page 12).
Signal Name HOST
DTE Pin ACX DCE Pin Notes
RD 2 2 (source) Received Data output from ACX
TD 3 (source) 3 Transmitted Data output from
HOST
Signal GND 5 5
DSR 6 6 (source) ACX +15V output through pull up
resistor
RTS 7 (source) 7 H/W Handshaking control signal
from HOST
CTS 8 8 (source) H/W Handshaking control signal
from ACX
Chassis
GND 9 9 Non-standard connection.
Connect to only one end of cable
shield.
Case X X Chassis GND connection. Connect to only one end of cable
shield.
CAUTION !!
DO NOT connect pins 7 and 8
together. This could cause
the ACX to discontinue trans-
mitting requested data.
See JC serial command for
more details of the RTS
and CTS control.
CAUTION !!
If commands are received from
the system controller too
quickly for the ACX to respond,
subsequent commands may be
lost.
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4.3 Hardware Handshaking
Hardware handshaking requires the following serial command to activate:
JC1<
Hardware handshaking is deactivated by sending the serial command:
JC0<
See “HARDWARE HANDSHAKING” on page 29 for additional information.
Figure 5: DIP Switch Location in ACX3200 and ACX3400
Figure 6: Typical DIP Switch S1 Positions, RS-232
Table 3: DIP Switch Settings
1 Default switch setting
2 Refers to models ACX32010 and ACX3401 Only
Baud
Rate S1-1 S1-2
Parity S1-3 S1-4
2400 OFF OFF No Parity OFF1OFF1
4800 OFF ON Even Parity ON OFF
9600 ON1OFF1Odd Parity ON ON
19200 ON ON 1 Stop Bit OFF1OFF1
12002OFF OFF 2 Stop Bits OFF ON
FRONT REAR
S1 S2
DANGER
SHOCK HAZARD
Disconnect power from ACX3200
or ACX3400 before making
adjustments to remove the risk
of electrocution or damage to
the electronics.
CAUTION !!
The ACX contains fragile and
static-sensitive components.
Exercise extreme care when
making adjustments.
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4.4 RS-422 Interface
All ACXxx11 models can be configured with an RS-422 electrical interface. In
this configuration, the standard serial protocol may be used but with a dedicated
serial line. To enable RS-422, move switch S1-3 and S1-5 to the ON position.
Figure 7: Typical DIP Switch S1 Positions, RS-422
4.5 RS-485 Interface
The RS-485 port, used on all ACXxx11 models, is the primary interface for con-
trolling the ACX. The RS-485 interface factory settings are 9600 baud, 8 bit
character and 1 stop bit. The parity bit is replaced by a 9th data bit used to indi-
cate whether the 8 bit character is an address or text character. Baud rate set-
tings can be changed using switches S1-1 and S1-2, as listed in Table 3.
Switches S1-3 and S1-4 must remain in the OFF position, switch S1-5 must be
in the ON position. In this configuration the ACX may be networked with up to 32
separate devices that conform to the RS-485 interface. Refer to the RS-485 sec-
tion for additional information (page 50).
Figure 8: Typical DIP switch S1 position, RS-485
Switches S2-1 and S2-8 must be ON if the ACX is the farthest logical device
from the host controller. All intermediate ACX controllers must have switches
S2-1 and S2-8 OFF. For two-wire operation, turn on switches S2-6 and S2-
7.(refer to “Factory Default Switch Positions” on page 15)
Table 4: Typical RS-485 DB9 Configuration
Signal Name HOST
DTE Pin ACX DTE Pin Notes
IN+ 8 (source) 8 Received Data+ output from HOST
IN- 3 (source) 3 Received Data- output from HOST
Signal GND 5 5 Application may not be required
OUT+ 6 6 (source) Transmitted Data+ output from ACX
OUT- 7 7 (source) Transmitted Data- output from ACX
Chassis
GND 9 9Non-standard connection, connect
to only 1 end for cable shield only
Case X X Chassis GND connection. Connect to only one end of cable for cable
shield only
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Additional information on RS-485 communication is provided in Section 10.0:
RS-485 SERIAL INPUT/OUTPUT, page 50.
4.6 Selecting Number of CM Inputs
The ACX operates with one or two CM inputs. To configure the ACX for the num-
ber of CMs in the system, set switch S2-2 as defined below:
Table 5: CM Selection
The default range of CM2 is 10 Torr and CM1 is 100 Torr. To change from the
default settings, send the “Set CM Full Scale” command for each CM. Refer to
Section 6.0: SERIAL INTERFACE, page 22 formore detailed information. When
using two CMs, CM1 must be the HIGH range unit. For local operation with the
ACX3400, access the “Sensor Range” command with the keypad and display
(see “Sensor Range” on page 20).
4.7 Selecting Input and Output Voltage Levels
The ACX input and output voltages for the analog setpoint, pressure and valve
angle are user configurable. The factory default settings are 0-10 VDC for both
input and output voltages. Use DIP switches S1-7 and S2-5 to change the con-
figuration. See Table 6, below, for switch configurations.
Table 6: Output Voltage
Switch S1-6 selects analog voltage output for one or two CMs. With S1-6 in the
OFF position, the analog output will indicate 0-5 VDC or 0-10 VDC representing
0-100% of the high range sensor. With S1-6 in the ON position, the analog out-
put will indicate 0-5 VDC or 0-10 VDC representing 0-100% of each sensor. Pin
4 on the Auxiliary Port indicates which CM is active, (see Table 30 on page 55).
Number of CMs S2-2
1OFF*
2ON
*Default switch setting
Function Switch 0-10 VDC 0-5 VDC
Analog Pressure/
Valve Angle
Output Range S1-7 OFF* ON
Analog Setpoint
Input Range S2-5 OFF* ON
* Factory default switch settings
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