VMIC VMIVME-4941 User manual

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VMIVME-4941
QUAD-CHANNEL RESOLVER-TO-DIGITAL
CONVERTER BOARD
INSTRUCTION MANUAL
DOCUMENT NO. 500-004941-000 N
Revised December 18, 1995
VME MICROSYSTEMS INTERNATIONAL CORPORATION
12090 SOUTH MEMORIAL PARKWAY
HUNTSVILLE, AL 35803-3308
[phone]
1-800-322-3616
FAX NO.: [phone]
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NOTICE
The information in this document has been carefully checked and is
believed to be entirely reliable. While all reasonable efforts to ensure accuracy
have been taken in the preparation of this manual, VMIC assumes no
responsibility resulting from omissions or errors in this manual, or from the use
of information contained herein.
VMIC reserves the right to make any changes, without notice, to this
or any of VMIC’s products to improve reliability, performance, function, or
design.
VMIC does not assume any liability arising out of the application or
use of any product or circuit described herein; nor does VMIC convey any
license under its patent rights or the rights of others.
For warranty and repair policies, refer to VMIC’s Standard Conditions
of Sale.
AMXbus, BITMODULE, COSMODULE, DMAbus, IOWorks, IOWorks
Access, IOWorks Foundation, MAGICWARE, MEGAMODULE, PLC
ACCELERATOR, QUICK-R-NET, Soft Logic Link, SRTbus, TESTCAL, “The Next
Generation PLC”, The PLC Connection, TURBOMODULE, UCLIO, UIOD, UPLC,
Visual IOWorks, Visual Soft Logic Control, VMEaccess , VMEmanager ,
VMEmonitor , VMEnet, VMEnet II, VMEprobe , and WinUIOC are trademarks of
VME Microsystems International Corporation. The VMIC logo, I/O man figure,
and UIOC are registered trademarks of VME Microsystems International
Corporation. Other registered trademarks are the property of their respective
owners.
VME Microsystems International Corporation
All Rights Reserved
This document shall not be duplicated, nor its contents used for any
purpose, unless granted express written permission from VMIC.
Copyright © January 1986 by
VME Microsystems International Corporation
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DOC. NO. 500-004941-000 N
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06/01/88
06/06/88
06/16/88
09/14/88
09/21/89
11/07/89
01/03/89
08/06/90
02/05/91
07/12/91
06/26/92
10/12/95
12/18/95
Release with Appendix A
Table of Contents, Sections 2, 3, 5, and 6
Table of Contents, Sections 2, 3, 4, and 5
Appendix A
Convert Manual to Microsoft
Cover, Pages ii, 2-6, and Appendix A
Cover, Page ii, and Appendix A
Cover, Pages ii, 2-6, 5-6, and Appendix A
Cover, Page ii, and Appendix A
Cover, Page ii, and Appendix A
Cover, Pages ii, v, vi, Sections 2 and 6,
and Appendix A
Cover, Pages ii, vi, and 4-2
Cover, Pages ii, 4-4, and 5-3 through 5-5
88-0026
88-0124
88-0134
88-0189
89-0096
89-0153
89-0166
90-0080
90-0233
91-0102
92-0218
95-0592
96-0004
RECORD OF REVISIONS
REVISION
LETTER DATE PAGES INVOLVED CHANGE NUMBER
VME MICROSYSTEMS INT'L CORP. PAGE NO.REV LTR
12090 South Memorial Parkway •
Huntsville, AL 35803-3308 [phone] ii
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iii
VMIC
SAFETY SUMMARY
THE FOLLOWING GENERAL SAFETY PRECAUTIONS MUST BE OBSERVED DURING ALL
PHASES OF THE OPERATION, SERVICE, AND REPAIR OF THIS PRODUCT. FAILURE TO
COMPLY WITH THESE PRECAUTIONS OR WITH SPECIFIC WARNINGS ELSEWHERE IN THIS
MANUAL VIOLATES SAFETY STANDARDS OF DESIGN, MANUFACTURE, AND INTENDED USE
OF THIS PRODUCT. VME MICROSYSTEMS INTERNATIONAL CORPORATION ASSUMES NO
LIABILITY FOR THE CUSTOMER’S FAILURE TO COMPLY WITH THESE REQUIREMENTS.
GROUND THE SYSTEM
To minimize shock hazard, the chassis and system cabinet must be connected to an
electrical ground. A three-conductor AC power cable should be used. The power
cable must either be plugged into an approved three-contact electrical outlet or used
with a three-contact to two-contact adapter with the grounding wire (green) firmly
connected to an electrical ground (safety ground) at the power outlet.
DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE
Do not operate the system in the presence of flammable gases or fumes. Operation of
any electrical system in such an environment constitutes a definite safety hazard.
KEEP AWAY FROM LIVE CIRCUITS
Operating personnel must not remove product covers. Component replacement and
internal adjustments must be made by qualified maintenance personnel. Do not
replace components with power cable connected. Under certain conditions,
dangerous voltages may exist even with the power cable removed. To avoid injuries,
always disconnect power and discharge circuits before touching them.
DO NOT SERVICE OR ADJUST ALONE
Do not attempt internal service or adjustment unless another person, capable of
rendering first aid and resuscitation, is present.
DO NOT SUBSTITUTE PARTS OR MODIFY SYSTEM
Because of the danger of introducing additional hazards, do not install substitute parts
or perform any unauthorized modification to the product. Return the product to VME
Microsystems International Corporation for service and repair to ensure that safety
features are maintained.
DANGEROUS PROCEDURE WARNINGS
Warnings, such as the example below, precede only potentially dangerous
procedures throughout this manual. Instructions contained in the warnings must be
followed.
WARNING
DANGEROUS VOLTAGES, CAPABLE OF CAUSING DEATH, ARE PRESENT IN THIS SYSTEM.
USE EXTREME CAUTION WHEN HANDLING, TESTING, AND ADJUSTING.
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!
OR
OR
WARNING
***************
***************
*
*
**
*
*
CAUTION
SAFETY SYMBOLS
GENERAL DEFINITIONS OF SAFETY SYMBOLS USED IN THIS MANUAL
NOTE:
iv
Instruction manual symbol: the product is marked with this symbol when it
is necessary for the user to refer to the instruction manual in order to
protect against damage to the system.
Indicates dangerous voltage (terminals fed from the interior by voltage
exceeding 1000 volts are so marked).
Protective conductor terminal. For protection against electrical shock in
case of a fault. Used with field wiring terminals to indicate the terminal
which must be connected to ground before operating equipment.
Low-noise or noiseless, clean ground (earth) terminal. Used for a signal
common, as well as providing protection against electrical shock in case
of a fault. Before operating the equipment, terminal marked with this
symbol must be connected to ground in the manner described in the
installation (operation) manual.
Frame or chassis terminal. A connection to the frame (chassis) of the
equipment which normally includes all exposed metal structures.
Alternating current (power line).
Direct current (power line).
Alternating or direct current (power line).
The WARNING sign denotes a hazard. It calls attention to a procedure, a
practice, a condition, or the like, which, if not correctly performed or
adhered to, could result in injury or death to personnel.
The CAUTION sign denotes a hazard. It calls attention to an operating
procedure, a practice, a condition, or the like, which, if not correctly
performed or adhered to, could result in damage to or destruction of part
or all of the system.
The NOTE sign denotes important information. It calls attention to a
procedure, a practice, a condition, or the like, which is essential to
highlight.
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500-004941-000
v
VMIVME-4941
QUAD-CHANNEL RESOLVER TO DIGITAL
CONVERTER BOARD
TABLE OF CONTENTS
Page
SECTION 1. INTRODUCTION
1.1 INTRODUCTION...............................................................................1-1
1.2 FUNCTIONAL DESCRIPTION ..........................................................1-1
1.3 REFERENCE MATERIAL..................................................................1-2
SECTION 2. PHYSICAL DESCRIPTION AND SPECIFICATIONS
SECTION 3. THEORY OF OPERATION
3.1 BLOCK DIAGRAMS ..........................................................................3-1
3.2 GENERAL DESCRIPTION................................................................3-1
3.3 VMEbus FOUNDATION LOGIC ........................................................3-1
3.4 RESOLVER CONVERTER MODULES.............................................3-4
3.4.1 Introduction........................................................................................3-4
3.4.2 Digital Interface..................................................................................3-6
3.4.3 Solid State Differential Input Option...................................................3-6
3.4.4 Direct Input Option.............................................................................3-6
3.4.5 Logic Input/Output.............................................................................3-6
3.4.6 Dynamic Performance.......................................................................3-7
3.4.7 Built-in-Test (Internal to the Converter)..............................................3-7
3.5 BUILT-IN-TEST (ON-BOARD)...........................................................3-7
3.6 PITCH COUNTER OPERATION.......................................................3-8
SECTION 4. PROGRAMMING
4.1 REGISTER MAP................................................................................4-1
4.2 PITCH COUNTER(S)/REGISTER(S) ................................................4-1
4.3 RESOLVER-TO-DIGITAL CONVERTER DATA REGISTER.............4-1
4.4 CONTROL AND STATUS REGISTER (CSR) ...................................4-7
4.4.1 Built-in-Test Programming.................................................................4-8
4.4.2 Fail LED Control ................................................................................4-8
4.4.3 R/D Converter Resolution Control .....................................................4-8
4.4.4 R/D Converter Bandwidth Control .....................................................4-11
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TABLE OF CONTENTS (Continued)
Page
SECTION 5. CONFIGURATION AND INSTALLATION
5.1 UNPACKING PROCEDURES...........................................................5-1
5.2 PHYSICAL INSTALLATION ..............................................................5-1
5.3 JUMPER AND SWITCH LOCATIONS...............................................5-1
5.4 ADDRESS MODIFIERS ....................................................................5-3
5.5 ADDRESS SELECTION SWITCHES................................................5-3
5.6 EXTERNAL POWER SELECTION....................................................5-3
5.7 REFERENCE VOLTAGE INPUTS.....................................................5-4
5.8 COUNTER DIRECTION JUMPERS..................................................5-6
5.9 JUMPERING FOR DIRECT vs DIFFERENTIAL SIGNAL INPUTS....5-6
5.9.1 Direct Input Option.............................................................................5-6
5.9.2 Differential Input Option.....................................................................5-6
5.10 Cabling Requirements.......................................................................5-9
SECTION 6. MAINTENANCE
6.1 MAINTENANCE.................................................................................6-1
6.2 MAINTENANCE PRINTS...................................................................6-1
LIST OF FIGURES
Figure Page
3.1-1 Functional Block Diagram..................................................................3-2
3.2-1 Input Configuration Software Control.................................................3-3
3.4.1-1 Resolver-to-Digital Converter Module Typical 1 of 4 .........................3-5
3.6-1 Pitch Counter Logic Functional Block Diagram..................................3-9
4.1-1 Register Map for Word Addressing....................................................4-5
4.1-2 Register Map for Longword Addressing ............................................4-6
5.3-1 Location of Jumpers and Switches....................................................5-2
5.5-1 Address Selection Switch Example (Address 0000) and Address
Modifier Switch Example (Short Supervisory Access).......................5-3
5.6-1 Jumper Installation to Select ±15 V Inputs via the P3 Connector......5-4
5.6-2 Jumper Installation to Select ±15 V Inputs via the P2 (Backplane)
Connector..........................................................................................5-4
5.7-1 Jumper Installation to Select the Reference Voltage Input at P3
for All Four Channels.........................................................................5-5
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TABLE OF CONTENTS (Concluded)
LIST OF FIGURES (Concluded)
Figure Page
5.7-2 Jumper Installation to Select a Single Reference Voltage Signal
from P2 (Pins C29 and C27) for All Four Channels...........................5-5
5.7-3 Jumper Installation to Select a Separate Reference Voltage
Signal for each Channel via the P2 Connector..................................5-6
5.9.1-1 Jumper Configuration for the Direct Signal Input Option (2 Volt),
this Configuration Connects S1 to S4 on Each Resolver Input
Channel.............................................................................................5-9
5.9.2-1 Jumper Installation to Select Single-Ended R/D Converter Inputs
(11.8 V Option Only), These Jumpers Connect a Ground to the S1
and S4 Inputs for All Four Channels..................................................5-9
5.10-1 Recommended Connection of Resolver Reference Voltage
and Signals........................................................................................5-10
LIST OF TABLES
Table Page
4.1-1 Address Register Map.......................................................................4-2
4.1-2 Address and Register Bit Definitions.................................................4-3
4.3-1 Resolver-to-Digital Converter Data Register and
Bit-Weight Table................................................................................4-7
4.4-1 CSR HI Byte Bit Map ($XX10)...........................................................4-9
4.4-2 CSR M-HI Byte Bit Map ($XX11).......................................................4-9
4.4-3 CSR M-LO Byte Bit Map ($XX12)......................................................4-9
4.4-4 CSR LO Byte Bit Map ($XX13)..........................................................4-9
4.4.1-1 CSR Relay Control Functions............................................................4-10
5.8-1 Jumper Installations for Counting Up When R/D
Data is Increasing..............................................................................5-7
5.8-2 Jumper Installations for Counting Down When R/D is Increasing .....5-8
5.10-1 P2 and P3 Connector Pinouts ...........................................................5-11
APPENDIX
A Assembly Drawing, Parts List, and Schematics
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SECTION 1
INTRODUCTION
1.1 INTRODUCTION
The VMIVME-4941 is a VMEbus compatible Quad Channel Resolver-to-
Digital Converter Board. Its features include:
a. Quad R/D converters
b. Tracking rates up to 800 rps minimum (48,000 RPM)
c. Software programmable resolution (10-, 12-, 14- or 16-bit)
d. Software programmable bandwidth (530 Hz, 130 Hz)
e. 16 bit pitch counter per channel
f. 8, 16, or 32 bit data transfers
g. Reference frequency from 360 Hz (Lo Bandwidth) to 6 k Hz
h. Status indications for loss of signal and tracking error over 65 bits
i. Accuracy to ±2.3 ARC minutes available (optional)
j. Double Eurocard form factor
k. Built-in-test capability with loss of signal and level of error fail LEDs
1.2 FUNCTIONAL DESCRIPTION
The Quad Channel Resolver-to-Digital Converter Board consists of
VMEbus compatibility logic, four resolver-to-digital converters, four 16-bit pitch
counters, and logic to support fault isolation to the channel level using a resolver
test signal that must be supplied via the P2 backplane user I/O pins.
VMEbus compatibility logic controls data transfers to the on-board
registers allowing 8-, 16-, or 32-bit transfers. The compatibility logic also contains
address decoding enabling the board to be addressed within the short I/O address
space.
Four independent R/D converters provide the user with the capability to
convert four resolver input channels. The R/D converters feature programmable
resolution and bandwidth. The resolution selection provides the user with the
capability of programming 10, 12, 14, or 16 bits.
The resolver board is designed for use in modern, high performance
commercial and industrial control systems applications including motor control,
radar, antenna position information, CNC machine tooling, robot axis control, and
process control.
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1.3 REFERENCE MATERIAL
The reader should refer to "The VMEbus Specification" for a detailed
explanation of VMEbus. "The VMEbus Specification" is available from the following
source:
VITA
VMEbus International Trade Association
10229 N. Scottsdale Road
Scottsdale, AZ 85253
[phone]
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SECTION 2
PHYSICAL DESCRIPTION AND SPECIFICATIONS
REFER TO 800-004941-000 SPECIFICATION
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500-004941-000
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SECTION 3
THEORY OF OPERATION
3.1 BLOCK DIAGRAMS
The Quad Resolver Input Board design may be partitioned into five
primary functional blocks (refer to Figure 3.1-1):
a. VMEbus foundation logic
b. Register selection and control
c. Test control logic
d. Resolver converters
e. Pitch counters and control logic
3.2 GENERAL DESCRIPTION
The VMIVME-4941 is designed for use in modern high performance
commercial and industrial control systems. Applications include motor control,
radar antenna position information, CNC machine tooling, robot axis control, and
process control.
The VMIVME-4941 utilizes four versatile state-of-the-art resolver to digital
converters featuring programmable resolution and bandwidth. Resolution
programming allows selection of 10, 12, 14 or 16 bit and options are available with
accuracy to 2 minutes +1LSB (+4LSB Diff Lin.). Resolution programming combines
the high tracking rate of 10 bit converters with the precision of 16 bit converters.
The Quad Resolver-To-Digital Converter Board is designed with test
capability for operational verification of all resolver hybrid converter modules and
the VMEbus control logic. The user may provide an input test signal via the P2
VMEbus expansion connector for board testing. A front panel fail LED is
illuminated at power-up and may be extinguished via program control after
diagnostics are successfully executed. Front panel status indicators are also
provided to indicate a loss of signal and level of error faults.
3.3 VMEbus FOUNDATION LOGIC
The VMEbus foundation logic is designed to support the standard data,
address, and control signal buffering. The data transfer logic supports long word
transfers to provide the user with the capability of reading an R/D converter and its
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500-004941-000
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P2
*
CONTROL
LOGIC
REGISTER
SELECT &
CONTROL
DATA
TRANS-
CEIVERS
ADDRESS
AND
COMPARE
LOGIC
RO
R1
R2
R3
INPUT
AND TEST
CONTROL
LOGIC
P3
(ONLY)
R/D
CH 0
R/D
CH 1
R/D
CH 2
R/D
CH 3
V
M
E
b
u
s
P1
16
16
32
32
32
32
32
+15 VDC
-15 VDC
+5 VDC
GND
RH
RL
GND
+15 VDC
-15 VDC
GND
+5 VDC
RH
-15 VDC
+15 VDC
RL
RH FROM P3 FIELD CONN.
TO R/D CONVERTERS
PITCH COUNTER
DATA (Typ)
R/D DATA (Typ)
SINGLE CHANNEL
RESOLVER INPUT
FROM P2 BACKPLANE
8-, 16-, OR 32-BIT
DATA TRANSFER
16-BIT
ADDRESSING
4 CHANNELSQUAD RESOLVER
INPUTS FROM FIELD
4 R/D CHANNELS
16
32
*VMIC SRTbus“ or VMEbus backplane.
POWER
& REF. VOLTAGE
JUMPERING
DC REFERENCE VOLTAGE (+5.5 V)
V
M4941/F3.1-1
Figure 3.1-1. Functional Block Diagram
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TEST CONFIGURATION
*One Control and Status Register bit controls all connections to P2.
R/D
CH 0
R/D
CH 3
R/D
CH 2
R/D
CH 1
P2
COS
SIN
COS
SIN
SIN
SIN
COS
COS
SIN
COS
BACKPLANE
TEST MODE*
FRONT PANEL
INPUT
P3
CONNECT CH0
CONNECT CH1
CONNECT CH2
CONNECT CH3
S1
S4
V
S1
(+5.5 VDC)
M4941/F3.2-1
Figure 3.2-1. Input Configuration Software Control
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500-004941-000
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associated 16 bit pitch counter with one transfer cycle. The data transfer logic also
supports 8 and 16 bit transfers.
3.4 RESOLVER CONVERTER MODULES
The four resolver-to-digital converter modules utilized are the ILC Data
Device Corporation RDC-19200 MONOBRID Series modules. The RDC-19200
Series Converters are versatile state-of-the-art resolver to digital converters
featuring programmable functions such as: resolution, bandwidth, and a scalable
velocity output voltage. Resolution programming allows selection of 10-, 12-, 14-,
or 16-bit. Models are available with accuracy to ±2 minute +1 LSB. Resolution
programming combines the high tracking rate of a 10-bit converter with the
precision of a 16-bit device in one module.
3.4.1 Introduction
The RDC-19200, includes three main parts: the signal input; a feedback
loop whose elements are the control transformer, demodulator, error processor,
VCO and up-down counter; and digital interface circuitry including various latches
and buffers. Either 11.8 V or 2 V resolver inputs are offered with the RDC-19200
series. The 11.8 V input is differentially coupled and the 2 V input is direct coupled.
The 2 V option eliminates the need for an input scaling network and allows
operation with a lower reference voltage. Figure 3.4.1-1 shows a typical DDC-
19200 used on the VMIVME-4941.
In a resolver, shaft angle data is transmitted as the ratio of carrier
amplitudes across the terminals. The internal converter operates with signals in
resolver format, sin Ωcoswt and cosΩcoswt. The feedback loop produces a digital
angle 0 which tracks the analog input angle • to within the specified accuracy of
the converter. The control transformer performs the following trigonometric
computation:
sin (Ω-0) = sinΩcos0 - cosΩsin0
Where Ωis the angle representing the resolver shaft position, and 0 is the digital
angle contained in the up/down counter. The tracking process consists of
continually adjusting 0 to make (Ω-0) equal to zero, so that 0 will represent the shaft
position •. The output of the demodulator is an analog DC level proportional to sin
(Ω•-0). The error processor receives its input from the demodulator and integrates
this sin(•-0) error signal which then drives a Voltage Controlled Oscillator (VCO).
The VCO's clock pulses are accumulated by the up/down counter. The velocity
voltage accuracy, linearity and offset are determined by the quality of the VCO.
Functionally, the up/down counter is an incremental integrator. Therefore, there are
two stages of integration which make the converter a Type II tracking servo. In a
Type II servo, the VCO always settles to a counting rate which makes d0/dt equal to
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500-004941-000
3-5
DDC NO. 19200
LOS
BIT
CH____ SIG LOS H
CH____ ERR65 L
S1
S2 + C
S3 + S
S4
CH ___ S1
CH ___ S2 COS
CH ___S3 SIN
CH ___ S4
REF
CB CH ___ CONV BUSY H
CH ___ REF
A
B
BW
U
MC
LSB
16
15
14
13
12
11
10
9
16
IDB16 TO IDB31
S
INH
EN6
+5 V
+5 V
GND
GND ENM
+15 V
+5
+15 V
+5 V
GND
-15
-15 V
8
7
6
5
4
3
2
1
(MSB)
CH ___ SEL RES AH
CH ___ SEL RES BH
CH ___ SEL HI BANDWIDTH H M CARRY L
CNT UP H
M4941/F3.4.1-1
Figure 3.4.1-1. Resolver-to-Digital Converter Module Typical 1 of 4
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500-004941-000
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dΩ/dt without lag. The output data will always be fresh and available as long as the
maximum tracking rate of the converter is not exceeded.
The converter automatically zero-sets all of the internal op amps twice
per carrier cycle near the zero crossings of the reference. This contributes to the
converter’s superior dynamic performance.
3.4.2 Digital Interface
The digital interface circuitry has three main functions: to latch the output
bits so that stable data can be read out; to furnish parallel, three-state data formats;
and to act as a buffer between the internal CMOS logic and the external TTL logic.
3.4.3 Solid State Differential Input Option
This option provides signal and reference inputs that are true differential
inputs with high AC and DC common mode rejection. Input impedance is
maintained with power off. The maximum transient peak voltage should not exceed
100 volts.
3.4.4 Direct Input Option
The direct input option provides for 2 Vrms resolver inputs. A 2 V input
from a resolver means that the reference voltage can be less than that of an 11.8 V
resolver, thus lowering the cost and power of the reference oscillator. However,
operation at a lower level makes the input more noise sensitive.
3.4.5 Logic Input/Output
The digital angle output consists of 10, 12, 14, or 16 parallel data bits and
a CONVERTER BUSY (CB) signal. All logic outputs are short-circuit proof to
ground and +5 volts. The CB output is a positive, 0.4 to 0.7 µs pulse. Data
changes about 50 ns after the leading edge of the pulse because of an internal
delay. Data is valid 0.2 µs after the leading edge of CB, and the angle is
determined by the sum of the bits at logic "1". Digital outputs are three-state and
provide two bytes; bits 1 through 8 (MSB) are enabled by the signal EM and bits 9
through 16 (LSB) are enabled by the signal EL.
Whenever an input angle change occurs, the converter changes the
digital angle in 1 LSB steps and generates a converter busy pulse. Output data
change is initiated by the leading edge of the CB pulse, delayed by 50 ns nominal.
Valid data is available at the outputs 0.2 µs after the leading edge of CB.
As long as the converter maximum tracking rate is not exceeded, there
will be no lag in the converter output. If a step input occurs, as when power is
initially applied, the response will be critically damped. After initial slewing at the
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500-004941-000
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maximum tracking rate of the converter, there is one overshoot (which is inherent in
a Type II servo). The overshoot settling to final value is a function of the small
signal settling time.
Resolution control is via two logic inputs, A and B. The resolution can be
changed during converter operation so the appropriate resolution and velocity
dynamics can be changed as needed. To insure that no race conditions exist
between counting and changing the resolution, inputs A and B are latched
internally on the trailing edge of CB.
Direction Output (U) is a logic "1" to count up and logic "0" for down. The
logic level at (U) is valid 0.5 µs before and 0.5 µs after the leading edge of CB.
Either low or high bandwidth can be selected by using the BW logic input.
A logic "0" applied to BW will select low bandwidth (130 Hz nom.); a logic "1"
selects high bandwidth (530 Hz nom.). Bandwidth can be changed during
converter operation.
3.4.6 Dynamic Performance
A Type II servo loop (Kv = •) and very high acceleration constants give
the RDC-19200 superior dynamic performance, as listed in the specifications. If the
power supply voltages are not within the ±15 VDC nominal values (5%), the
specified input rates for full accuracy will increase or decrease in proportion to the
fractional change in voltage.
3.4.7 Built-in-Test (Internal to the Converter)
The RDC-19200 provides two useful logic outputs for systems self tests.
The Built-In-Test output (BIT) monitors the level of error (D) and, if it exceeds
approximately 65 bits, the logic level at BIT will change from logic "1" to logic "0".
This condition will occur during a large step and reset after the converter settles out.
BIT will also be set for an over-velocity condition because the converter loop cannot
maintain input/output sync, and if the converter malfunctions where it cannot
maintain the loop at a null. For system safety, the Loss Of Signal (LOS) output is
useful. The LOS signal will change from logic "0" to "1" if both resolver inputs are
disconnected, resulting in unpredictable converter performance.
3.5 BUILT-IN-TEST (ON-BOARD)
The Built-in-Test feature of the VMIVME-4941 requires a separate digital
to resolver converter board. Built-in-Test is performed under software control in
which the D/R output board is used as a resolver input for the VMIVME-4941. The
VMIVME-4941's CSR is programmed to connect all four R/D modules to the P2
resolver input channel. Thus, a digital word is transferred to the D/R board and can
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500-004941-000
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be read back on all channels and a software compare performed on the digital
data. Using this scheme all R/D converters can be tested in the same software test
loop. The reader should refer to Section 4 for additional programming details. A
front panel Fail LED is initialized on during power-up reset and may be
extinguished via program control upon successful completion of diagnostics.
Because this product is designed to utilize the DC reference voltage from channel 0
for the test signal input to all four modules, this functional test is accurate to within
20 counts (the user should expect a 20-count error).
3.6 PITCH COUNTER OPERATION
The 16-bit pitch counters utilize the direction and carry outputs from the
R/D modules to count the number of revolutions. Control logic is provided (refer to
Figure 3.6-1) to ensure synchronous writing/reading/counting.
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