Industrial Automation Protocols


Process Control Industrial Automation Protocols

Automation Protocol TypeTechnology DeveloperYear IntroducedGoverning StandardsOpenness
ARCNETDatapoint / SMC1975ANSI 878Chips, boards, ANSI docs
AS-IAS-I Consortium1993Submitted to IECAS-II, C, Market items
CAN openPhillips / CiA1992CiA6 chip vendors 100+ products
CONTROL NETAllen Bradley1997Controlnet InternationalChip from AB multiple vendors with products
DEVICE NETAllen Bradley1994ISO 11898 &115196 chip vendors 100+ products
FOUNDATION FIELD BUSFieldbus Foundation1995ISA SP50 / IEC TC65Chips / software from multiple vendors
INDUSTRIUAL ETHERNETIntel / DEC /Xeros; HP Hirschmann synergetics1979;1998IEEE 802.3Multiple vendor support through Industrial Ethernet trade association
INTERBUS-SPheonix Contact1984DIN 19258Product from over 400 manufactures
LON WorksEcholon Corp1991ASHRAE OF BAC netPublic documentation on protocol
MODBUS PLUSAEG Modicon1981NoneControlled by AEG modicon. Multiple vendor support through Modconnect vendor program
PROFIBUS DP/PAProfibus Trade OrganisationDP:1994 PA:1995DIN 19245 part 3/4Product from over 150 vendors
SDSHoneywell1994Honeywell spec submitted to IEC, ISO119896 chip vendors 200+ product
SERIPLEXAPC Inc1990Seriplex SpecChips available multiple interfaces
WORLD FIPWorld FIP1988IEC 1158-2Multiple chip vendors

Physical Characteristics

Automation Protocol TypeNetwork TopologyPhysical MediaMaximum Devices (Nodes)Maximum Distance
ARCNETBus, Multidrop, StarTwisted pair coax fiber255 nodes6 km
AS-IBus, Ring,tree,star of allTwo wire cable31 slave100 m          300m with repeaters
CAN opentrunkline / droplineTwisted -pair for signal and power64 nodes500 m
CONTROL NETTrunkline, tree, starCoax R6/U fiber99 nodes5 km coax,   30 km fiber
DEVICE NETTrunkline / droplie with branchingTwisted – pair for signal and power64 nodes500 m
FOUNDATION FIELD BUSMultidrop with bus powered devicesTwisted pair240/segment 6500 segments1900m @31.25 kbps 500m @2.5 Mbps
INDUSTRIUAL ETHERNETStar, bus10Base-T, 10Base-FL (fiber)          100 Base-Tx48 bit address of    247 nodes1500m
INTERBUS-SSegmented with T dropsTwisted-pair, fiber, slip ring256 nodes400m/segment 12.8 km total
LON WorksBus, ring, loop, starTwisted-pair, fiber, power line3200 / domain2000 m @ 78kbps
MODBUS PLUSMultidrop network segment with bridge capabilitiesRS-485, transformer isolated32,64 max per segment. Max 5 level routing1500 ft(450M) repeaters can extend 6000 ft(1800M)
PROFIBUS DP/PALine star & ringTwisted Pait or fiber127 nodes24 km (fiber)
SDSTrunkline / droplineTwisted pair for signal and power64 nodes, 126 address500m
SERIPLEXTree, loop, ring, multidrop star4-wire shrouded cable500+ device500+ ft
WORLD FIPBusTwisted-pair, fiber256 nodesup to 40 km

Transport Mechanism

Automation Protocol TypeCommunication methodsNetwork SpeedData Transfer SizeArbitration MethodError CheckingDiagnostics
ARCNETPeer to Peer31.25kbps to 10 Mbps508 bytesToken16 bit CRCBuilt in
AS-IMaster/slave with cyclic polling167 kbps31 slaves with 4 in and 4 outMaster/slave with cyclic pollingManchester code hamming-2 partlyslave fault device fault
CAN openMaster/slave1Mbps,    500 kbps, 250 kbps, 125kbps8 – bytes variable messageCarrier-sonac multiple accessCRC checkBus monitor
CONTROL NETMaster/slave, multi-master, peer to peer5 Mbps510 bytesTime -slice multiple access (CTDMA)CCITT with 16 bit polynomialDevice slave faults
DEVICE NETMaster/slave, multi-master, others500 kbps, 250 kbps, 125 kbps8-bytes variable messageCarrier-sonac multiple accessCRC checkBus monitoring
FOUNDATION FIELD BUSClient/server publisher/subscriber, Event notification31.25 kbps 1 Mbps    2.5 Mbps16.6 M objects / deviceDeterministic centralised scheduler, multiple backup16 bit CRCRemote diagnostics network monitors, parameter status
INDUSTRIUAL ETHERNETCSMA/CD10 Mbps 100 Mbps1500 bytes dataCollision detection32 bit CRCCD, network management
INTERBUS-SMaster/slave with total frame transfer500 kbps, full duplex512 bytes h,s., unlimited blocksNone16 bit CRCSegment location of CRC error and cable break
LON WorksMaster/slave Peer tp peer1.25 Mbs full duplex228 bytesCarrier sense multiple access16 bit CRCDatabase of CRC error and device error
MODBUS PLUSToken passing1 Mbps256 bytes data + headerPeer to peer Token passing16 bit CRCLocal chip and software
PROFIBUS DP/PAMaster/slave Peer to peerDP upto 12 Mbps Pa 31.25 kbps244 bytesToken passingHD4 CRCStation,module & channel diagnostics
SDSMaster/slave, peer to peer, multicase, multi-master1 Mbps,   500 kbps, 250 kbps, 125 kbps8 – bytes variable messageCarrier-sonac multiple accessCRC checkBus monitoring diagnostic slave
SERIPLEXMaster/ slave Peer to peer200 Mbps7680 / transferSonal multiplexingEnd of frameCabling problems & echo check
WORLD FIPPeer to peer31.25 kbps, 1&2.5mbps, 6Mbps fiberNo limit, variables 128 bytesCentral arbitration16 bit CRC data “freshness” indicatorDevice message time-out, redundant cabling


Automation Protocol TypeCycle time: 256 discrete 16 nodes with 16 I/O’sCycle time: 128 analog 16 nodes with 8 I/O’sBlock transfer of 128 bytes 1 node
ARCNET<2 ms @ 2.5 mbps<2ms @ 2.5 Mbps<2 ms @ 2.5 Mbps
AS-I4.7 msNot possibleNot possible
CAN openNot availableNot availableNot availavle
CONTROL NET2 ms2 ms2 ms
DEVICE NET2.0 ms master / slave polling10 ms master / slave polling4.2 ms
FOUNDATION FIELD BUS100ms@31.25kbps < 1ms @ 2.5 Mbps600 ms @ 31.25 kbps <8ms @ 2.5 Mbps36 ms @ 31.25 kbps 0.45 ms @ 2.5 mbps
INDUSTRIUAL ETHERNETNetwork dependentNetwork dependentNetwork dependent
INTERBUS-S1.8 ms7.4 ms140 ms
LON Works20 ms5 ms @ 1 Mbps5 ms @ 1 Mbps
MODBUS PLUSNot availableNot availableNot availavle
PROFIBUS DP/PAConfiguration dependent typical   < 2 msConfiguration dependent typical < 2 msNot availavle
SDS<1ms event driven< 1ms per event 10.4 ms2 ms @ 1 mbps
SERIPLEX1.32 ms@200kbps, m/s10.4 ms10.4 ms
WORLD FIP2 ms @ 1 Mbps5 ms @ 1 Mbps5 ms @ 1 mMbps

Summary of Process Control Industrial Automation Protocols

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2 thoughts on “Industrial Automation Protocols”

  1. I have tank radar( TH43 CP 2A TO) with just primary output for this model output=TRL/2 BUS,MODBUS PROTOCOL. So what is type of modbus? and what is the TRL/2 bus. If I want to convert this output to modbus tcp/ip what should I bring about the type of converter and about the terminal of output I found (+4 to 20 ma or bus) and (-4 to 20 ma or bus ) about 4 to 20 ma is this yield signal and can I take this as analog signal and if I invest bus what should I do ?

  2. Hello,

    You can use level transmitter modbus output to connect to the respective modules. You can use either TRL/2 or Modbus or Analog signals. Check your transmitter complete part number. From this you can get the available options (outputs) in the transmitter from the vendor.

    I think you already have modbus output. You can use the same to retrieve your process parameters. In general, you already have compatible transmitters and devices/gateways in your panel. please check.

    You have to check the respective tank gauging technical documents supplied by vendor.


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