VB Series

VB Series: VME-Bus Synchro - Resolver LVDT I/O Cards


  • Synchro, Resolver, and LVDT Converters
  • Mix-Match any 4/8 Converterss/Cards
  • Transformer Isolated I/O Options
  • Loop-Back Testing Cards Available
  • Proven “Industry Standard Converters”
  • Reliable Register Based “LSI” Logic
  • Quadrature Incremental Encoder Outputs
  • On-Board Reference Supplies


The “VB Series” product lines contains VME compatible synchro/resolver converters and absolute encoder systems. These particular cards are ideal for any rotary motion and related process, control, or simulator type application with any VME compatible system.

The VB Series provide up to eight channels of resolver or synchro conversion on a single width, standard 6U height VME card.

The VBE Series Resolver/Encoder systems feature up to 6 axis of shaft angle position encoding with a choice of single or multiturn resolvers used as the sensor inputs.

CCC’s full line of “Industry Standard” Synchro/Resolver converters, and Absolute Encoder products, are used to populate standard multifunction VME decoder cards. Differing converters may be mixed to minimize real estate for a particular application.

Both industrial and military grade (extended) temperature range versions are available, with forced air or conduction cooled models having thermal layers and expansion wedge style card locks. Accuracy applies over the operating temperature range, and 883 level B/38510 parts/processing is available on all units.

Transformer isolation is offered for all inputs and outputs, eliminating concerns for ground loops, differing potentials and high voltage field transients affecting the card itself and the VME Bus backplane.

All input cards feature Built-In Fault Detect, Self-Test command angle is optioned, and models with True Wrap Around Test (VBT's).

Maximum versatility has been employed on all “VB” products to assure universal compatibility in addressing, timing, system, and microcomputer independence.

All VB Series converter cards are configured as A24:D16 DTB Slaves. They will respond to address modifier codes “3D” or 39 for standard addressing, and "2D" or "29" when selected for short I/O type addressing.

The VME interface is a very straightforward register based design; simply address the channel and read or write the data.

Status registers are used to provide card configuration data, and on a per channel basis, to provide channel config. and fault status.

The high speed register based interface allows these cards to operate reliably in any software environment, with uninhibited Real-Time performance.

Buffered latches are provided on all data lines to assure stable read and write cycles as commanded by the host. Address and control lines feature single point terminations to minimize any loading of the backplane. All signal output converters are provided with inherent read-back ability.

No external Power Supplies are required, every card is available as powered with standard + 12 an +5V VME Bus standard supplies. Power source jumpers are provided to select the +12VDC power input source, via the external connector port, or the VME BUS P1 backplane. CCC's VB cards include two 25 pin polarized "D" style subminiature connectors on the front panel for all external I/O, and/or the P2 connector I/O is available as an option.

The availability of Self-Test Command Angle options (-WS), and True Wrap-Around loop back-test boards (VBT and VBDT Series), allow the user to configure automatic self test and simulation type programs at any level.

Because the VB Series uses proven, and reliable “whole” converter products, coupled with the use of leading edge LSI interface technology, the VB Series cards offer quick availability, competitive pricing and the best density verses performance ratio available in the marketplace.

The VB S/R series are 1-4 channel continuously tracking synchro or resolver to VME card converters, employing a type 2 ratiometric conversion loop for high speed/ high performance applications. They will accept any of 4 individual, or paired 3-wire synchro or 4-wire resolver inputs over a frequency range of 50 to 10KHZ., and convert them simultaneously into 10-16 bit words of natural binary data. Data is addressable in a single word 16 bit format over the VME backplane.

Data made available to the bus is continuously updated (tracking) without interruption; output data is stable, accurate, and always fresh up to the maximum tracking rate of the converter. When address and control variables are set, all data bits are latched simultaneously into separate buffered registers to prevent false reads.


No external transformers, modules or signal conditioning is required. The synchro/resolver converters used feature internal solid-state or transformer Scott T’s that accept direct field voltage inputs.

Transformer isolated units are completely isolated from each other and the backplane for all the reference and signal lines. This completely isolates the card and effectively the whole computer from all field wiring, eliminating concerns over troublesome ground loops, differing potentials, ground interjected spikes, or ghostly field noise that so frequently takes down entire systems.


The VBR Hardware inherently supports four channels of discreet S-D/R-D conversion, two channels of multispeed/multiturn S-D/R-D conversion, or a combination of both.

The Firmware supports simultaneous two channel store-to-read configuration required to properly interrogate multispeed/multiturn resolvers and synchro's. Furthermore, precombined converters can be supplied as an option.

Bus Powered

Power required is +15 and +5VDC as standard; +12VDC is optioned, and the source for the +12 or +15V input is strap selectable for power sourcing via the backplane or externally powered via the I/O connector.


All units include a continuous built-in-test, converter and I/O fault detect, and -WS option units include a command to 30 degree test angle for self-test. Options currently available include DC velocity output, a built-in-test output representing the tracking mode, internal reference supplies, quadrature incremental pulse train outputs, mil-grade extended temperatures, and 883 level B processing.

The VBW Series are complete VME Bus to Synchro and Resolver output converters used for self-test, simulation and control, in military and industrial applications. The VBW card is populated with digital to: synchro, resolver, or DC sine/cosine converters mixed as specified for the application.

The converters are continuously updating, allowing the speed response to be dictated by the software, clock and the CPU.

All of these synchro and resolver converters feature virtually indestructible short-circuit proof outputs, overvoltage and transient protection, internal heat sinks, current limiting, and automatic thermal cutoff.

Complete transformer isolation is offered for all reference inputs and signal outputs to eliminate ground loops, differing potentials,and to keep any high voltage transients fromaffecting the VME bus backplane.

Both low cost “DSL/DRL Series”, and “DSP Series” reference powered converters are offered to drive on-board loads of up to 5VA, and external “booster amplifiers” are available to drive loads up to 300VA.


The VBW series consists of up to 4 channels digital of synchro or resolver converters in a single slot width , 6U size, standard VME Bus module. Only the DSP Converters require a double width slot because of their .82" height modules.

Configured as a A24:D16 DTB Slave, these cards will respond to address modifier codes “3D or 39” for standard addressing, and “2D or 29” when selected for short I/O type addressing. The D00 through D15 data lines are used for the command input, whereby D15 represents the most significant bit.

VBW cards are provided with inherent Read-Back functionality, and Loop-Back/ Wraparound testing features can be provided as an option (see VBT Series, data sheet).

Because the DSL/DRL series converters are offered with VME Bus standard +12V and +5VDC supplies, and the DSP series are completely "Reference Powered" units; No external power supplies are required. These features make the VBW VDSL Series the highest performance, easiest to use and most accurate complete units available in the marketplace.


The DSL/DRL converters are highly reliable, very low cost, digital to synchro/resolver converters that are powered from +15VDC or Bus-powered +12volt supplies. The DC supply source may be field selected as sourced by an external input or, powered from the VME Bus backplane.

Frequencies of 400Hz. and higher require no external components, and two different types of output transformers are offered for the 60Hz. units.

The internal; reference and signal transformers, rugged power amplifiers, and large internal heat sinks, provide complete output drive with the best density verses heat dissipation per square inch, available for DC powered converters in the marketplace.


The DSP converters derive the output power from the reference (RH, RL) input, and require No +15 or +12VDC supplies. This series features a very efficient, internal pulsating power supply, that converts the reference input into a high-power, angle-weighted synchro output format.

Because these units convert the AC reference input directly into AC modified outputs; they are more like a translator then amplifier, they effectively transfer the AC power rather then amplify DC sources. This allows the DSP series converters the inherent ability to provide superior efficiency and 2-3 times better thermal heat dissipation over DC powered units, in addition to the ability to provide high voltage 60 Hz. signals direct, without any external transformers.

400Hz DSP units drive up to a full 4.5VA load, and 60Hz units drive a full 1.5VA load direct without requiring external output transformers.

Synchro/Resolver active Control Transformers, active Control Differentials, units with Isolated D-A (Digital to Analog), or LVDT/RVDT, Multispeed Conversion, Demods' active Vector Generators etc. can be configured by requesting: "VBW Series Extended Model Selection guide".


The VBT and VBDT Cards are full function 3 and 6 channel VME Bus cards with added support logic for CCC’s "Advanced Random Signal Test Bus TM" (ARS T-Bus TM).

The "ARS T-BusTM" uses a interlocked relay switching matrix, that allows all the signal lines from one converter module to be selectively routed to any other compatible converter modules, that reside on the same card, or any other VBT or VBDT Card tied into the system.

Compatible modules on any board are allowed to be tied between, or to, each other for loopback, wraparound testing and real time systems test.The ARS T-BusTM facilities Real-Time on-line (live) and off-line testing, and program controlled automatic testing down to the component converter level.

Because the ARS T-BusTM allows the program to run “live” (real-time testing) or, selectively disconnect the actual field wired signal lines in route to each converter; Automatic System Debug, can easily discern converter verses field wiring or sensor faults in the overall system, and evaluate the differences between loaded and unloaded converter performance.

Multiple Inter-Board Test Paths

The on-board ARS T-BusTM may be user strapped for routing to any one of two different and distinct inter-card test buses that are daisy chained between boards via the P2 expansion port or the Front Panel (T-BusTM) connector ports.

The use of two-different inter-card test buses allows the user to run separate high voltage synchro, and low voltage synchro buses within the same system. Furthermore, the two different Inter-card buses can be staggered for expansion into a third RVDT/LVDT test bus, or even a fourth or fifth multichannel A-D/D-A test bus etc.

Test Bus Integrity

Unlike other test methods that employ stepping up/down signal voltages for testing, or fixed step changes to verify limited functionality; the “ARS T-BusTM” routes the real (true voltage) signal lines as they enter the circuit card, this permits 100% true testing ability.

The use of real (true-voltage) signal lines, and a true isolated test bus for Loop-Back allows the program to discern positively, (with confidence) whether a failure is an on-board or field fault.

Safe-LockTM Control Logic

The ARS T-BusTM uses a unique register based control structure employing the use of CCC's "Safe-Lock TM control logic". A single Safe-LockTM Command Register is provided to request the desired routing of signals, and a Safe-LockTM Status Register is provided to confirm if and when the commanded routing is set.

All the ARS T-BusTM; interlock, non-contention, bus-busy, time-out and signal compatibility checking logic, is transparent to the user, and automatically controlled with the on-board Safe-LockTM control logic.

Application Testing

Loop-back testing is primarily used immediately following power-ups, to step the converters through a user programmed exercise.

Real-time testing is performed by monitoring the signals and converters while in operation, and/or comparing the actual performance with another channel in the system (running concurrent to the live channel being tested), or a simulation of the expected.

The use of 100% transformer-isolated converters and a physically isolated test bus switching matrix; allows users to integrate Automatic Test Systems with guaranteed confidence and 100% assured performance.


Computer Conversions VBD Series are ultra high density Synchro & Resolver Converter Cards designed specifically for VME Bus applications where density, isolation, and cost is of paramount importance.

Up to a full 8 channels of Synchro/Resolver to Digital or 6 channels of Digital to Synchro/ Resolver conversion are provided on a single slot width, 6U size, VME Bus Card.

Even with this high a density; the VBD cards are offered with a selection of solid-state or on-board Transformer Isolated I/O.


Transformer isolated units are completely isolated from each other and the backplane for each converters set of signal lines, and the reference inputs are transformer isolated separately for each pair of converters, or optionally individual; allowing the user to run 8 different reference input sources, levels, or frequencies, into the same VME Converter Card.

This completely isolates the card and effectively the whole computer from all field wiring, eliminating concerns over troublesome ground loops, differing potentials, ground interjected spikes, ghostly or field noise that so frequently takes down entire systems.

Each pair of two Converters shares a Status Register having individual converter fault bits for each channel, +12 or +15V power loss detection, and converter configuration details. All the S-D/R-D Converters are complete ratiometric, continuously updating tracking converters employing the use of internal type-two of solid state servo-loops for highspeed closed loop performance. They are insensitive to amplitude, and frequency variations, providing a lag free virtually dynamic response all the way up to their maximum specified tracking rate.


All units include a continuous built-in-test, converter and I/O fault detect, and -WS option units include a command to 30 degree test angle for self-test.

D-S/D-R Output Channels:

All the D-S/D-R Converters provide a fast 5 microsecond throughput, featuring continuous outputs and hybrid power short circuit protected amplifiers that will drive loads from 1.2 to 4.5VA.

D-S/D-R Converters with a 400 Hz. frequency drive 26 or 90 V.L-L signal outputs direct. Two different external output transformers are available for 50 or 60 Hz. applications, and external power boosters can be provided. Inherent Multiturn/Multispeed Support VBD Series Hardware supports both eight channels of discreet S-D/R-D conversion and/or four channels of multispeed/multiturn S-D/R-D conversion.

The standard Firmware supports simultaneous two channel store-to-read configuration required to properly interrogate multispeed/multiturn synchro’s or resolvers.

Multispeed Specific Models

VBDM style Cards are offered with up to four channels of specifically precombined Multispeed Synchro/Resolver to Digital, or up to 2 full channels of Digital to Multispeed Synchro/Resolver Converters on a double slot width 6U size card. The VBDM Converter Cards feature precombined data; using a single linear non-ambiguous 16 bit data word for each multispeed channel. High Resolution single-slot width precombined units available too. Ratios of 1 & 36, 2 & 36, 1 & 32, 1 & 10, 1 & 8, etc. are standard available selections.

The primary advantages in using natural multispeed converter are: the single word 16 bit data handling, no software overhead for combining, and a very powerful R-D/S-D built-in-test bit that automatically tests both that the Converter is a) tracking the input, and b) whether the fine/coarse alignment error is or goes out of synch as a result of misalignment or broken wires.

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