Group3 I/O Modules
Introduction
CN3 modules house a processor card and any combination of 3 I/O boards.Device Interfaces are small control modules that house the Input and Output (I/O) boards in a Group3 system. They are available in two sizes, accepting one, or three I/O boards. There is now also a new integrated module available, designated CNA, that combines the functions of several components into one unit.
Each Device Interface unit contains a processor circuit board to handle the fiber optic loop communications, and to service the I/O boards.
A range of different I/O boards (analog inputs, analog outputs, digital channels, motor drivers etc.) allows flexible tailoring of each Device Interface to the control requirements at each point. Software resident in the Device Interface automatically recognises the I/O boards installed and configures itself to provide the appropriate control and monitoring features.
The product family has been designed for ease of mechanical installation. The units are physically small, and mount by simply clipping onto a standard 35mm DIN rail. The DI modules are powered by low-voltage ac or dc - either is accepted without adjustment.
Fiber optics are used for communication to reduce transient pickup, and to provide high voltage isolation.
The DI processor board incorporates several features to ensure reliable operation: in addition to the checks built into the microprocessor itself there is a separate supervisor (watchdog) chip to reset the microprocessor if it detects incorrect operation as a result of an unusually powerful electrical transient. The software running within the DI is of a multitasking nature, and one of the independent tasks is a dedicated self checking process that continually monitors all the other tasks and variables in the microprocessor. If anything is found to be out of normal bounds then a reset is forced.
A diagnostic port on each Device Interface allows system monitoring, configuring and debugging - a feature not previously available in a product of this type. The diagnostic port is invaluable at all phases of system commissioning. By using a standard terminal the engineer can access a Device Interface independently of the fiber optic communication loop. A built-in menu system provides for a wide range of diagnostic, simulation, and set-up functions. A restricted access level security system prevents undesirable tampering by unauthorised personnel.
Device Interface Specifications
| Type | Features |
|---|---|
| A |
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| B |
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| C |
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| D |
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| E |
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| F |
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| G |
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| H |
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| J |
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| K |
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| CNA Combined module |
|
Boards may be fitted in any combination, except only one type F or K board in a DI.
topSystem communications fiber optic loop
- Fiber optic cable
-
- HP HFBR Versatile Link series plastic cable - 40 meters max. per link
- Spectran HCS, silica core Versatile Link cable - 500 meters max. per link
- H-P HFBR ST connectored glass cable - 3000 meters max. per link
Units on loop 16 max.
Loop address 0 through F (hexadecimal), set on switch accessible on the outside - Communication modes
-
- ASCII character strings at 9600 baud
- SDLC loop mode at 1.152 Mbaud
- DI to DI communications mode
Diagnostic port: mini-DIN receptacle for connecting to any standard RS-232C serial terminal
Serial data format ASCII character strings, 9600 baud NRZ, 7 data bits, 2 stop bits, even parity no handshaking, standard levels
- Power requirements
-
accepts AC, or DC of either polarity
- AC: 12 to 24V, 26Vrms absolute max., 10VA max.
- DC: 12 to 30V, 34V absolute max., 7W max.
Motor driver I/O boards require additional power -
Galvanic isolation 200V min. between power input and active circuitry
Ambient temperature: Operating 0 to 55°C, Non-operating -20 to 75°C
Memory retention Configuration stored for 10 years min.
Device Interface Boards - Quick Reference Guide by Function
DI processor
- Power requirements AC: 12 to 24V or DC: 12 to 30V
- Diagnostic port data RS232, 9600 baud, 7 data & 2 stop bits, even parity
- Fiber Optics Transmit port is closest to mounting plate, receive closest to front.
Digital Channels: Type A and Type B boards
- Maximum applied voltage 40 volts.
- Input thresholds TTL levels, internal 1kW pullup to +5 volts.
- Output Drivers Open collector, 40 volt 100mA max. - sink to ground.
Analog Inputs: Type A and Type C boards
- Selectable ranges Full scale of 50mV, 5V, 10V, unipolar or bipolar
- Input resistance 180kΩ
- Maximum input voltage ±30V
Analog Outputs: Type A, Type D and Type J boards
- Output ranges 5V, 10V, unipolar and bipolar
- Minimum resistive load 2kΩ
DC Motor Drivers: Type E board
- Maximum drive 30 volts, 1 amp for each motor
Serial Comms Ports: Type F board
- Fiber Optics Hewlett Packard Versatile Link plastic core cable.
Stepper Motor Drivers: Type G board
- Maximum drive 50 volts, 180mA from the I/O board directly, or generates logic signals for external power drivers.
Encoders: Type H board
- Maximum input rate 120 kHz with 1 board in DI, 40 kHz with 3 boards in DI.
GPIB / IEEE 488: Type K board
- Controller , Talker and Listener on the IEEE 488 bus
Device Interface I/O Boards
Each DI has space in it to house either one, two, or three I/O boards. The I/O boards connect together, and to the processor board, by way of a row of pluggable interboard connectors.
If control requirements change, an I/O board can be removed from a DI and a different type of I/O board put in its place. A DI can be filled with any combination of I/O boards. The exception is that there should only be one type F - (serial communications board), or one type K - (GPIB / IEEE 488 controller) in a DI. On power up the processor board interrogates the I/O boards in the DI and configures itself and the I/O boards according to pre-stored settings.
topType A Fast Analog and Digital I/O Board
This board provides 2 analog inputs, 1 analog output and 8 digital channels. Designed as a high speed board, all channels are capable of being updated 500 times / second.
Specifications
Analog Inputs
| Parameter | Specification |
|---|---|
| Resolution | 16 bit |
| Ranges |
|
| Digital span | bipolar -32,000 to +32,000, unipolar 0 to 64,000 |
| Input Resistance |
|
| Common mode rejection ratio | 80dB min. |
| Common mode input voltage range | ±12V (Maximum input voltage ±30V) |
| Input settling time | 5ms to 0.01% of full scale step |
| Input latency | 10ms max. |
| Offset tempco | 10mV/°C max. |
| Gain tempco | 50ppm/°C max. |
Analog Output
| Parameter | Specification |
|---|---|
| Resolution | 14 bits |
| Accuracy | 0.1% |
| Digital span |
|
| Output ranges |
|
| 1 bit change |
|
| Output current load | 5mA max. (Short circuit output current 25mA) |
| Output impedance | 100Ω max. |
| Load impedance | 2kΩ min, 1m F max. |
| Offset tempco | 20mV/°C max. |
| Gain tempco | 50ppm/°C max. |
| Output settling | 2 ms to 0.01% of full scale step |
Digital I/O
- Output drivers open collector
- OFF state Internal 1kW pull-up to +5V
- ON state 1 volt max. at 100 mA sink to ground
- Input compatibility TTL switching levels, 40 volt max.
Connectors
- Digital 20-way double-row 0.1" spacing shrouded header.
- Analog 10-way double-row 0.1" spacing shrouded header.
- accepts flat ribbon cable socket connector.
Type B 24 Channel Digital I/O Board
This board provides 24 bi-directional digital channels. The channels have open collector drivers for use as outputs, and TTL compatible levels for inputs. Each channel can be used as an input or as an output.
The board can be connected directly to the popular Opto 22 Digital I/O Mounting Rack system using standard 50-way flat ribbon cable.
Specifications
Number of channels 24, individually configurable as inputs and outputs.
Maximum allowed voltage on any signal pin: 40 volts
Outputs
- Open collector, sink to ground.
- OFF state internal 1kW pull-up to +5V
- ON state 1 volt max. at 100 mA sink to ground.
- On power up all outputs are cleared to OFF.
Behaviour of the outputs on a watchdog or software self check RESET can be set by a jumper to either HOLD the outputs at their last value, or CLEAR the outputs to OFF.
Inputs
- TTL voltage level compatibility.
- Maximum input low level is 0.8 volts.
Connector
- 50-way double-row 0.1" spacing shrouded header.
- accepts flat ribbon cable socket connector.
Type C 8 Input Analog Board
This board provides eight analog input channels. The channels have differential inputs, and provide 16 bit resolution.
Each channel can be set individually to have one of four input ranges.
The user can select various time constants for a software based time averaging filter, and optionally a window within which the filtering is active.
Specifications
8 analog input channels, differential inputs.
| Parameter | Specification |
|---|---|
| Resolution | 16 bit |
| Input ranges |
|
| Digital span |
|
| Input Resistance |
|
| Common mode rejection ratio | 80dB min. |
| Common mode input voltage range | ±12V |
| Maximum input voltage | ±30V |
| Input settling time | 5ms to 0.01% of full scale step |
| Input latency | 10ms max. |
| Offset tempco | 10mV/°C max |
| Gain tempco | 50ppm/°C max. |
| Polling rate | 125 times per second each channel |
Connector
- 34-way double-row 0.1" spacing shrouded header.
- accepts flat ribbon cable socket connector.
Type D 8 Output Analog Board
This board provides eight single ended analog outputs of 14 bit resolution.
Specifications
Analog Outputs
p8 single ended outputs, referenced to a common analog ground.
| Parameter | Specification |
|---|---|
| Resolution | 14 bits |
| Accuracy | 0.1% |
| Digital span |
|
| Output ranges |
|
| Output current load | 5mA max. |
| Short circuit output current | 25mA |
| Output impedance | 100Ω max. |
| Load impedance | 2kΩ min, 1m F max. |
| Offset tempco | 20mV/°C max. |
| Gain tempco | 50ppm/°C max. |
| Output update rate | 125 times per second |
| Load impedance | 2kΩ min, 1m F max. |
Connectors
- 20-way double-row 0.1" spacing shrouded header.
- accepts flat ribbon cable socket connector.
Type E 4 DC Motor Driver Board
This board has four channels for controlling small D.C. motors. Each motor can have independently variable speed, direction and acceleration.
Drive to the motors is controlled by pulse density modulation; the cycle time is divided into 256 sections, each of one pulse width. The number of drive pulses, as set by the speed setting, are evenly distributed over the 256 pulse cycle time, resulting in much smoother drive at low speeds when compared to a simple pulse width modulated speed control.
The board includes a stable 5 volt reference output for energising position sensing potentiometers, which could be read using a type C analog input board.
Specifications
- Driver output channels
- 4, reversible, pulse density modulated
- Pulse width
- 0.02 to 3.54 ms programmable in 8 binary steps, giving total cycle times of 7 to 910 ms.
- Supply voltage
- 30 volts D.C. max. referenced to a common ground., each channel supplied individually.
- Load current
- 1 Amp max per channel
- Speed resolution
- 8 bits (1:256)
- Acceleration resolution
- 8 bits (1:256)
- Stop modes
- motor windings open-circuit, or short circuited (braking)
- Reference voltage output
- 5 ±0.1V, 10 mA max load, 30 mA short circuit
Connectors
- Motors 4-way AMP shrouded header
- accepts AMP Mod. IV Wire-Applied Housing 102241-3
- Reference 3-way AMP shrouded header, as above.
Type F 2 Serial Communications Ports
This serial interface board has two serial send/receive channels, and is used to interface devices with serial communications facilities into a Group3 Control system.
Specifications
| Parameter | Specification |
|---|---|
| Ports | two, completely independent |
| Serial Baud Rates |
|
| Number of data bits | 7 or 8 |
| Parity | even, odd, or none |
| Number of stop bits | 1 or 2 |
| String terminator (receive) | any ASCII character, printing or control |
| Flow control | X-OFF/X-ON (CTRL-S/ CTRL-Q) |
| Buffering | 1000 byte on each port, transmit and receive. |
Fiber optic cable Hewlett Packard HFBR series, 40 meters max. length
topType G 4 Stepping Motor Driver Board
This board generates the logic levels necessary to drive 4 stepping motors. Each channel has independently programmable acceleration and final sustained speed.
Each motor can be set to Position mode, or to Continuous Run mode, in which the motor acts as a variable speed drive. Position control is achieved by sending the channel a 32 bit number representing the desired absolute position ( ±2,147,483,648 steps from a settable zero). The I/O board then calculates the direction, acceleration and speed required, and generates the signals to move the motor there.
The acceleration can be set (0 to 255), the maximum step rate (0 to 5000 steps/sec), and in continuous run mode the direction (0=off, 1=forward, 2=reverse, 3=off, rotor locked).
The four drive signals generated for each stepping motor are provided as open collector outputs capable of sinking 180mA. In Quadrature drive mode small motors can be driven directly, or the signals can be used to drive high current devices. In the other drive modes, Clock & Direction, or Dual Clock output, this board generates logic signals that are used to control a commercially available stepper motor driver power module. Additional signals are provided to select Half or Full step, and All Windings Off.
Eight digital inputs are provided which can be set to act as limit switches, automatically shutting off drive to the motor, or they can used as general inputs.
Four analog inputs of eight bit resolution (values of 0 to 255) are available. They could be used as a fairly low resolution check on the absolute position, by sensing position potentiometers. A 5 volt reference is provided to power the pots.
Specifications
| Parameter | Specification |
|---|---|
| Number of motors | 4 |
| Output signals | open collector 180 mA, 50 V maximum |
| Pull up to motor power | 10kΩ |
| Input parameters maximum step rate | maximum step rate
|
| Desired position | ± 2,147,483,648 steps (32 bit) from zero |
| Accelerations | 256 levels (8 bit) |
| Input signals | digital inputs 1kW pull up to 5 volts, to be switched to ground maximum input 5V minimum input 0V analog inputs maximum input 5V minimum input 0V converted to 8 bit digital value, 20mV per bit. |
| output current | 5V reference (total both pins) 50 mA recommended potentiometer value 500Ω minimum. |
| Connector type | 20-way double-row 0.1" spacing shrouded header. Accepts flat ribbon cable socket connector. |
Type H 4 Stepping Motor Driver Board
The Type H Encoder Board accepts inputs from four quadrature encoders. A dedicated up/down counter for each encoder allows the four channels to operate independently and at high speed.
Applications include rotary position encoders, shaft speed detectors, and 'soft pot' operator interface control knobs (such as the Hewlett-Packard HRPG series of miniature encoders).
Specifications:
- Number of encoders
- 4
- Input signals
- 2 quadrature signals per channel, LO level <1.5V, Hi level >3.5V
- Noise rejection
- inputs have 2 Volts hysteresis, and are digitally filtered
- Input pulse repetition rate
-
- 120kHz max. With 1 I/O board in Device Interface
- 80kHz max. With 2 I/O boards in Device Interface
- 40kHz max. With 3 I/O boards in Device Interface
- Supply to Encoders
- +5 Volts, 50 mA each Maximum, 200 mA total.
Connectors
- 5-way AMP shrouded header
- accepts AMP Mod. IV Wire-Applied Housing 102241-3
Type J Dual Precision Analog Output Board
This board provides two single ended analog outputs of 16 bit resolution.
Specifications
| Parameter | Specification |
|---|---|
| Resolution | 16 bits |
| Accuracy | 0.005% |
| Monotonicity | 16 bit |
| Digital span |
|
| Output ranges |
|
| 1 bit change |
|
| Short circuit duration | indefinite |
| Short circuit current | 20 mA |
| Output impedance | 1Ω max. |
| Load impedance | 1 KW min. |
| Offset tempco | 20mV/°C typ. |
| Gain tempco | 5ppm/°C typ. |
Connector
- 3-way 0.1" spacing shrouded header.
- accepts AMP Mod. IV Wire-Applied Housing 102241-3
Type K GPIB / IEEE 488 Controller
The Type K I/O board provides full GPIB/IEEE488 talker/listener/controller capability over the fiber optic loop of a Group3 Control system.
Power supplies, controllers and measuring instruments with a GPIB interface can now be integrated into the computer control system, taking advantage of the high voltage isolation provided by the fiber optic cables.
A maximum of 8 GPIB devices can be controlled by one type K board.
Specifications
- Performs all IEEE 488.1 interface functions.
- Meets all IEE 488.2 requirements.
GPIB/IEE488 Capability
- SH1 - Source handshake
- AH1 - Acceptor handshake
- T5 or TE5 - Talker or Extended Talker
- L3 or LE3 - Listener or Extended Listener
- SR1 - Service request
- RL1 - Remote/local
- PP1 / PP2 - Parallel Poll local/remote configuration
- C1,C2,C3,C4,C5 - Controller, all capabilities
- E1,E2 - bus drivers tri-state/open collector
Connector
- 26-way double-row 0.1" spacing shrouded header.
- accepts flat ribbon cable socket connector.
CNA module Integrated Device Interface
The CNA is a precision control and monitoring module that is designed to be used as part of a Group3 Control system. It is functionally equivalent to a type A board and Processor and the signal conditioners all rolled into one unit.
The CNA can also implement closed loop control, as it has PID algorithm built in to it.
It is housed in a low profile metal case, and is designed as a very rugged, small, inexpensive unit to aid the implementation of a distributed control system.
The unit consists of a main circuit board contained entirely within a metal enclosure, linked by a short length of 40way ribbon cable to an I/O board (SCA) mounted on top of the case.
Specifications
Two Analog Input channels,
16 bit resolution, bipolar, each with differential inputs.
- Input Ranges:
- 10 Volt (1 lsb = 0.3mV)
- 100mV (1 lsb = 3µV )
- Input Impedence:
- model CNA-1 94kW
- model CNA-4 100MW
Both channels sampled 30 times per second.
Channel 0 can be used as the feedback input, if PID control is selected.
One Analog Output channel.
16 bit resolution,
Output signal selectable as:
- -10 to +10 volt range, (1 lsb = 0.3mV)
- 4 to 20 mA current output. (1 lsb = 0.2 µA)
output Impedence 100W
The analog output acts as the closed loop PID control output, if selected.
Eight Digital Inputs
Opto-couplers on each channel can be selected to operate in two modes:
- Signal powered channels are completely independent, require minimum of 5mA signal.
- Contact closure channels share a common return potential (which is isolated from the rest of the unit up to 500V)
Eight Digital Outputs
- Reed relay contacts, Switching 100 volt, 500mA maximum.
- Max. switched power - 10W
- Isolation of contacts from rest of unit - 300 volts
Communications by fiber optic cables at 1.15Mbaud. Entire unit is isolated from the controlling computer.
Power supply input required:
18 to 36 volt DC, or 14 to 26 volt (rms) AC, 3 Watts.
Unit contains an internal switch mode supply, providing isolation up to 200 volts.
Fully featured Diagnostic Port, allowing configuration and local control over-ride from a terminal with an RS-232 serial port.
Two stage transient suppression
All I/O pins on the main board have fast acting, voltage limiting components installed, coupled with further suppression and isolation on the I/O board.
Connectors
- Analog channels on I/O board - each has a 4 position screw terminal block, 3.81mm pitch
- Digital channels on I/O board - each has a 3 position screw terminal block, 3.81mm pitch
- Between the boards - 40 pin dual row 0.1" spacing boxed header on main board,
- 40 way ribbon cable with matching socket attached to I/O board.
- Diagnostic Port - 8 way miniDIN round socket.
- Power connector. Phoenix MSTB, 2 pole connector
- Data - Fiber optics - Hewlett Packard Versatile Link plastic cable connector,
- ST connector for glass cored cable
Case
- Aluminium extrusion 140 x 92 x 29 mm
- Stainless steel endplates with integral DIN rail locking system.
Mounting
- Stainless Steel DIN rail clamp is integral to the metalwork of the unit.