Description...Master & Slave I/O Nodes are economical when large concentrations of points are in each process location (see page 4). System Architectures A Peer-to-Peer System is used
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• Complete I/O Options. Available modules incorpo-rate 8 to 21 channels per I/O brick to handle current,voltage, RTD, thermocouple, digital, and relayprocess signals.
• Distributed, Sensor-Level I/O Saves Money. TheI/O EXPRESS will handle up to 7,812 monitoringand control points, eliminating the need to runexpensive point-to-point wiring to dispersed fieldlocations.
• Industry-Standard MODBUS RTU Communication.Universal RS-485 communication protocol providestrouble-free interface with popular MMI and SCADAsoftware packages, PC, PLC and DCS systems, andwith other networkable instrumentation.
• Transmit Any Distance, Over Any Terrain. Use atwisted wire pair, fiber optic cable, radio link, ortelephone modem data link to overcome rugged,long-distance, normally impassable, and hazardousenvironments
• Standard Redundant Communication Links.Every I/O EXPRESS has dual communication linksthat help assure uninterrupted data transfer.
March 1999 Data Sheet 14.12
The I/O EXPRESS delivers hundreds of ways to cost-effectively interface dispersed, field-mounted monitor-ing and control devices with computer-based equip-ment and readout devices. A versatile money-saverand problem-solver, the I/O EXPRESS is a:
Long-Distance Field MultiplexerConcentrate just a few—or up to 7,812—monitoringand control signals on to a MODBUS RTU digital com-munication link. Then safely send the data miles be-tween the field and the control room. You’lldramatically reduce wire, conduit, installation, andoverall signal transmission costs.
Distributed I/O SystemConvert noise-sensitive sensor and analog signals tonoise-immune digital signals in the field... before theycan be damaged during long-distance transmissionthrough a noisy plant.
Solution for Every IndustryThe I/O EXPRESS is the economical answer for anarray of distributed I/O needs: chemical and petro-chemical production plants; tank farms; water/waste-water pump stations; oil/gas distribution lines; pulpand paper mills; food processing plants; facility light-ing control; environmental and pollution control sys-tems; and utilities.
Distributed Data System
Features
Description
All product names are registered trademarks of their respective companies.
Flexible I/O EXPRESS distributed I/O provides a multitude ofinnovative solutions for saving time and money in industrialmonitoring and control applications.
Control
Monitor
MODBUS RTUCommunication Link
Distributed I/ONetwork
PCDCSPLC
Figure 1. The I/O EXPRESS is the perfect distributed I/O front endfor PC, DCS and PLC-based systems.
Distributed Data System
Why Distribute Intelligence?Distributed I/O NetworksThe I/O EXPRESS substantially reduces costs bymultiplexing multiple process signals onto oneMODBUS RTU (RS-485) digital communication link.This eliminates the need to install expensive point-to-point wiring for each monitoring and control point.
Versatile module types and system architecturesprovide an economical solution for both small and largedata acquisition and control strategies.
Module TypesMasterless I/O Modules operate as complete, stand-alone I/O stations. Use these when a small-to-mediumnumber of points are in each location (see page 4).
Master & Slave I/O Nodes are economical when largeconcentrations of points are in each process location(see page 4).
System ArchitecturesA Peer-to-Peer System is used when multiple analogand digital signals need to be collected, multiplexed sothey can be economically transmitted long distances,and then returned to individual analog or digital signalsfor readout (see page 5).
A Peer-to-Host System is a cost-effective strategywhen reliable, distributed front end I/O hardware isneeded for a computer, DCS or PLC-based system(see pages 6 and 7).
OutputsAnalogDigitalRelay
InputsAnalogDigitalRTD*
Thermocouple*
Up to252 I/O
InputsAnalogDigitalRTD*
Thermocouple*
OutputsAnalogDigitalRelay
Master & SlaveI/O Node
MODBUS RTUCommunication Link
(RS-485)
* RTD and thermocouple input types available with Peer-to-Host Systems only.
Masterless I/O Modules
Distributed Data System
Masterless I/O Modules
Up to252 I/O
Peer-to-HostSystem
or
Peer-to-PeerSystem
OutputsAnalogDigitalRelay
Host Computer-Based SystemPersonal Computer (PC)Distributed Control System (DCS)Programmable Logic Controller (PLC)Work StationOther Host Computer Systems
Master & SlaveI/O Node
MODBUS RTU CommunicationFor the system’s RS-485 communication link, theI/O EXPRESS uses standard MODBUS RTU. This“open” protocol facilitates interface with numerouscomputer, DCS and PLC-based systems, third partysoftware packages, and other networkable instruments.
InputsAnalogDigital
InputsAnalogDigital
OutputsAnalogDigitalRelay
Distributed Data System
Module TypesFlexible module options offer solutions for collectingjust a few—or thousands—of signals from field devicesand/or delivering data to final control elements.
Masterless I/O ModulesMasterless Modules are the cost-effective strategywhen a small number of process points are located indispersed field locations (Figure 3). These stand-aloneI/O stations take input directly from, and/or outputcontrol signals directly to, field devices.
Available models handle current, voltage, RTD*,thermocouple*, digital, and relay signals, and 8 to 21channels per module (see the Ordering Specificationstable on page 11 for details). Any mix of I/O types maybe integrated into an I/O EXPRESS system.
Field Location 4
Figure 3. Masterless Modules are ideal when a small number of I/O points are required in dispersed field locations.
Field Location 3
Field Location 6
Field Location 5
Field Location 2
Field Location 1
MODBUS RTU Communication Link
Figure 4. Master and Slave I/O Nodes provide money- and time-saving field multiplexing when large quantities of I/O are in each fieldlocation.
AdditionalMaster & SlaveI/O Nodes
ToControlRoom
MODBUS RTU Communication Link
Slave Modules(Up to 12 perMaster)
AdditionalMasterlessModules
MasterlessModule
MasterModule
* RTD and Thermocouple inputs are available with Peer-to-Host Systems only.
ToControlRoom
Master & Slave I/O NodesUse Master & Slave I/O Nodes when large numbers ofpoints are in each process location (Figure 4).
Master Module —The same size as other systemmodules, the Master Module collects data from up to12 Slave Modules. It multiplexes the Slave’s multiplesignals, and sends the digitized data long distancesbetween the field and control room over a MODBUSRTU communication link
Slave Modules —These collect monitoring signalsfrom primary sensors, analog transmitters, and digitaldevices. Or, they deliver control signals to on/offdevices (relays, motors, pumps, etc.) and proportionalfinal control elements like valves and positioners. Upto 12 Slaves connect to the Master Module in a “Star”configuration. Slaves can be dispersed up to 50 feet(15 meters) from the Master Module. Available mod-ules handle 8 to 21 channels of current, voltage, RTD*,thermocouple*, digital, or relay signals (see OrderingSpecifications for details). Any mix of I/O types may beintegrated into a system.
Mixed SystemsWhen some locations have extensive I/O requirementsand others just a few, any combination of Masterlessand Master & Slave I/O Nodes integrate into a system.
Distributed Data System
Peer-to-Peer SystemsIn this architecture, for every module situated in thefield there is a matching module on the opposite end ofthe MODBUS RTU communication link.
Monitor and Control— For data acquisition, thesystem collects signals from analog transmitters anddigital devices. It multiplexes the signals, and sendsthe data to a matching module on the opposite side ofthe link. The matching module outputs the data inanalog or digital form for readout.
For control, multiple signals can be digitized by theI/O EXPRESS in the control room, and sent over thedata link to a matching module in the field. The field
module converts the signals back to analog or discreteform for proportional or on/off control.
There can be up to 8 pairs of Masterless Modulesper system. A full system handles up to 168 processpoints (21-Channel Modules x 8 Pairs perSystem = 168).
A Master & Slave I/O Node accommodates up to252 points (21-Channel Slaves x 12 Slaves perNode = 252 Points). This configuration expands toinclude up to 8 pairs of I/O Nodes, and up to 2,016points (21-Channel Slaves x 12 Slaves per Node x 8Nodes per System = 2,016).
A Peer-to-Peer System can include any combina-tion of up to 8 pairs of Masterless Modules, and/orMaster & Slave I/O Nodes.
Pair 1
Pair 2Outputs
Pair 3Inputs
Pair 4Outputs
Pair 5Inputs
Figure 5. A Peer-to-Peer System can be any mix of I/O types, and combinations of Masterless Modules and Master & Slave I/O Nodes.
MODBUS RTU Communication Link(RS-485)
Up to 252 Inputs & OutputsUp to 252 Inputs & Outputs
Pair 1
MasterlessModules
Up to 8 Pairs ofMasterless and/orMaster & SlaveI/O Nodes(Up to 2,016 I/O)
MasterlessModules
Master &SlaveI/O Node
Up to 8 Pairsof Masterlessand/orMaster & SlaveI/O Nodes(Up to 2,016 I/O)
Master & SlaveI/O Node
FIELD LOCATIONS CONTROL ROOM
Pair 2Inputs
Pair 3Outputs
Pair 4Inputs
Pair 5Outputs
Distributed Data System
Peer-to-Host SystemsThe I/O EXPRESS is the perfect I/O front end forcomputer-based distributed data acquisition andcontrol strategies.
Any Module Combination— Peer-to-Host Systemsmay incorporate any combination of MasterlessModules and/or Master & Slave I/O Nodes.
Connected in a multidrop network along thecommunication link, there can be up to 31 Masterand/or Masterless Modules per I/O EXPRESS system.Up to 7,812 I/O points can be accommodated(21-Channel Slaves x 12 Slaves per Master x 31Masters = 7,812).
Monitor and Control— For monitoring applica-tions, the I/O EXPRESS modules collect signals fromanalog transmitters, sensors (RTD and thermocouple),or digital devices. Signals are multiplexed in the field,and sent over the RS-485 communications link directlyto a computer-based host.
For control, process commands from the hostcomputer system are transmitted over the communica-tions link, and then converted to analog or digital format the opposite end for controlling valves, pumps,motors, and any other type of proportional or on/offfinal control element.
For direct interface, the host computer systemmust be equipped with an RS-485 computer card.Since most systems communicate via RS-232C, MooreIndustries LCM Link Converter Module can be used toperform the RS-232C to RS-485 conversion.
Any mix of up to 31Masterless Modulesand/orMaster & Slave I/O Nodes(Up to 7,812 I/O per System)
InputsAnalogDigitalRTD
Thermcouple
OutputsAnalogDigitalRelay
Masterless Modules
Up to252 I/O
Master & SlaveI/O Node
InputsAnalogDigitalRTD
Thermcouple
OutputsAnalogDigitalRelay
Figure 6. Peer-to-Host Systems deliver low-cost and versatiledistributed I/O.
Distributed I/O System
Compatible with MMI SoftwareOnce the computer-ready data is delivered to the hostcomputer or DCS, leading third-party Man Machine In-terface (MMI) software packages can be used to cre-ate custom data acquisition and control strategies:
• Intellution® FIX DMACS™
• USDATA® FactoryLink®
• Wonderware® InTouch™
• INTEC Paragon
• Ci Technologies Citect for Windows™
These, and other, available packages allow a multitudeof strategies that incorporate data acquisition, alarmsummary and management, data logging and report-ing, historical data collection and trending, and super-visory control functions.
Control
MainframeComputer
System
MODBUS RTUCommunication Link(RS-485)
Host Computer-Based SystemPersonal Computer (PC)Distributed Control System (DCS)Programmable Logic Controller (PLC)Work StationsOther Host Computer Systems
AdditionalWork StationsHigh Speed Local AreaNetwork (LAN)—DECNET,Token Passing Ring,ETHERNET, etc.
OPEN
OPEN
MIXER #1OFF
210°C35%
157°C51%
CATALYST
ALARM #1
SITE 2
CLOSED
REACTOR #1REACTOR #2
Monitor
Distributed Data System
Why Distribute Intelligence?Redundant COMM LinksEvery I/O EXPRESS module incorporates dualcommunication ports. For critical applications, dualcommunication links act as a safety net should one ofthe links be compromised (see Figure 7).
Both communication links continually operate, sothere is no interruption of data transfer if the primarylink is broken, and the secondary link must take over.For added safety, the links can even be run along twocompletely different paths without compromisingsystem performance.
120 Thermocouple Inputs
FieldCabinet
120Thermocouple
Inputs
Dual Links Add Flexibility —The dual link capabilitycan be used to provide unique data gatheringsolutions. For example, in Figure 8 the dual links areused to send identical data from multiple analog leveltransmitters to two separate readout locations.
At Location #1, digital data sent over the PrimaryCommunication Link is input to a computer where MMIsoftware is configured to display, chart, and archivetrending information.
At Location #2, the multiplexed signals are sentover the Secondary Communication Link, andconverted back to their original analog form forreadout on digital panel meters.
Figure 7. Redundant communications links assure continuous data flow should one of the links be compromised.
DCS
PrimaryMODBUS RTU Communication Link
Secondary MODBUS RTU Communication Link
ReactorVessel
Field Cabinet (Inside)
Master & SlaveI/O Node
Secondary COMM Link
Primary COMM Link
Distributed Data System
Figure 8. The I/O EXPRESS’s dual communication links can be used to simultaneously send identical process data to two separate locations.
Location #1Personal Computer
DisplayChart
ArchiveTrending
Troubleshooting
PrimaryMODBUS RTU Communication Link
SecondaryMODBUS RTU Communication Link
Location #216 Panel Meters
Readout
FluidHolding
Tank
FluidHolding
Tank
100.0
83.0
75.2
67.4
52.5
37.3
22.7
12.3
98.7
87.2
74.3
68.4
51.2
38.2
24.7
12.3
Eight4-20mA InputsfromLevelTransmitters
Eight4-20mA InputsfromLevelTransmitters
Primary and SecondaryCommunication Links maybe run along twocompletely separatepaths without compromisingsystem performance.
Why Distribute Intelligence?Versatile COMM Link OptionsVersatile communication link options overcome long-distance, normally impassable, and hazardousenvironments:
Twisted Wire Pair— The solution for the majority ofapplications, a standard 24AWG shielded twisted pairis a low-cost solution to send data long distances.
Telephone Modem— Inexpensively transmit processdata unlimited distances over leased or dial-uptelephone lines. We offer modems and RS-485 toRS-232C (for modem) converters.
Radio— Where wires can’t be run, such as over water,radio (RF) communication provides accurate andreliable signal transmission.
Fiber Optic Cable— For hazardous or exceptionallynoisy environments, light is an effective strategy. Weoffer all of the accessories needed for interface.
Distributed Data System
SpecificationsPerformance
(MasterModule)
Scan Rate: 12 Slavechannels updated every 50to 150 msec, dependingupon the I/O configuration ofthe connected Slave moduleIsolation: 500Vdc betweeneach COMM link; 500Vdcbetween either of the COMMlinks and power; and500Vdc between COMMlinks, power, and Slavemodules
Accuracy: ±0.15% of span(12-bit resolution)Scan Rate: Each channelupdated 200 times per sec.Isolation: 500Vdc betweeneach COMM link; 500Vdcbetween either of the COMMlinks and power; and500Vdc between COMMlinks, power, and inputchannels; 7Vdc, (commonmode) channel-to-channelImpedance: Current, 250Ω;Voltage, 1MΩ minimumCommon Mode Rejection:<115dB @ 60Hz
Accuracy: ±0.15% of span(12-bit resolution)Scan Rate: Each channelupdates 100 times per sec.Isolation: 500Vdc betweeneach COMM link; 500Vdcbetween either of the COMMlinks and power; and500Vdc between COMMlinks, power, and outputchannelsDrive Capability: 700ΩRipple: 1µA peak-to-peak
Accuracy: ±0.25% ofreading, ±0.25°CResolution: ±0.1°CScan Rate: Each channelscanned every 1.3 secondsIsolation: 500Vdc betweeneach COMM link; 500Vdcbetween either of the COMMlinks and power; and500Vdc between COMMlinks, power, and inputchannels
Accuracy: ±3°CResolution: 0.5°CUpdate Rate: Eachchannel scanned 200 timesper secondIsolation : 500Vdcbetween each COMM link;500Vdc between either ofthe COMM links andpower; and 500Vdcbetween COMM links,power, and input channelsImpedance: >10MΩSensor Burnout :Upscale Drive
Scan Rate: Each channelis updated 100 times persecondIsolation: 500Vdcbetween each COMM link;500Vdc between either ofthe COMM links andpower; and 500Vdcbetween COMM links,power, and input channelsImpedance : 3300ΩMaximum Input Voltage:30VdcThreshold: Guaranteedhigh state above 7V,guaranteed low state under0.5V
Scan Rate: Each channelupdated 100 times persecondIsolation: 500Vdcbetween each COMM link;500Vdc between either ofthe COMM links andpower; and 500Vdcbetween COMM links,power, and outputchannelsOutput Transistor Rating:Maximum ON current,200mA; Maximum OFFvoltage, 40Vdc
(Thermo-couple Input
Modules)
(Analog InputModules)
(AnalogOutput
Modules)
(RTDModules)
(Digital InputModules)
Scan Rate: Each channelupdated 100 times per secondIsolation: 500Vdc betweeneach COMM link; 500Vdcbetween either of the COMMlinks and power; and 500Vdcbetween COMM links, power,and input channels; and 250Vdcbetween output channelsContact Ratings: 8-channel(RO8) modules are SPDT, ratedfor 3A at both 24Vdc and110Vac:12-channel (RO12)modules are normally open(NO), SPST, rated for 1A at24Vdc, and 0.5A at 110Vac
Range: 1 mile (1.6 km) typicalon 24AWG wire at 19200 baud;2 miles at 4800 baud(transmission range isdependent on wire size,capacitance of wire andenvironment); 15 m (50 feet)between Master Modules andSlave ModulesBaud Rate: 2400, 4800, 9600,and 19200 rates areconfigurableThroughput Rate: Dependentupon number of modules insystem, baud rate, type ofCOMM link used; and totalCOMM link distance (consult thefactory for specifics for yourapplication)
11-30Vdc (2 to 4 watts for mostmodules-any analog current orrelay output has a 6 watt max.)
Operating Range: -5°C to+65°C (+23°F to +185°F)Storage Range: -25°C to+85°C (-13°F to +185°F)Relative Humidity: 10 to 90%,non-condensingAmbient Temperature Effect:from ±0.015% of span/°C to±0.02% of span/°C (depends onmodule type; consult the factoryfor details)
External jumpers used to setbaud rate and module address
580 g (1.7 lbs)
COMM Link
PowerSupply
Specifications subject to change. Printed in U.S.A.293-710-01 E
(RelayOutput
Modules)
AmbientConditions
Adjustments
Weight
(DigitalOutput
Modules)
Distributed Data System
DDS DIN A.B.S.Nylonhousingwithremovableterminalblocksmounts onstandardTop Hatrail(DIN46277-3)