FIELDBUS COMPARISON
(PROFIBUS, InterBus-S, CAN...)

I/O NETWORK COMPARISON

BACKGROUND INFORMATION

Technology Developer Year Introduced Governing Standard Openness
PROFIBUS DP/PA PTO DP-1994, PA-1995 DIN 19245 part 3/4 Products from over 150 vendors
INTERBUS-S Phoenix Contact 1984 DIN 19258 Products from over
400 manufacturers
DeviceNet Allen-Bradley March 1994 ISO 11898 &11519 6 chip vendors,
100+ products
ARCNET Datapoint/ SMC 1975 ANSI 878 Chips, boards, ANSI docs
AS-I AS-I Consortium Fall 1993 Submitted to IEC AS-II.C. Market item
Fieldbus Foundation Fieldbus Foundation 1995 ISA SP50/IEC TC65 Chips/software from multiple vendors
IEC/ISA SP50
Fieldbus		 ISA & Fieldbus F. 1992 - 1996 IEC 1158/ANSI 850 Multiple chip vendors
Seriplex APC, Inc. 1990 Seriplex spec Chips available multiple interfaces
WorldFIP WorldFIP 1988 IEC 1158-2 Multiple chip vendors
LonWorks Echolon Corp. March 1991 ASHRAE of BACnet Public documentation on protocol
SDS Honeywell Jan., 1994 Honeywell Specification, Submitted to IEC, ISO11989 6 chip vendors,
200+ products









PHYSICAL CHARACTERISTICS

Network Topology Physical Media Max. Devices (nodes) Max. Distance
PROFIBUS DP/PA Line, star & ring Twisted-pair or fiber 127 nodes 24 Km (fiber)
INTERBUS-S Segmented with "T" drops Twisted-pair, fiber, and slip-ring 256 nodes 400 m/segment, 12.8 Km total
DeviceNet Trunkline/dropline with branching Twisted-pair for signal & power 64 nodes 500m
ARCNET Bus, multidrop, star Twisted-pair coax fiber 255 nodes 5 miles
AS-I Bus, ring, tree star, of al Two wire cable 31 slaves 100 meters, 300 with repeater
Fieldbus Foundation Multidrop with bus powered devices Twisted-pair 240/segment, 65,000 segments 1900m @ 31.25K
500m @ 2.5M
IEC/ISA SP50
Fieldbus		 Star or bus Twisted-pair fiber, and radio IS 3-7
non IS 128		 1700m @ 31.25K
500M @ 5Mbps
Seriplex Tree, loop, ring, multi-drop, star 4-wire shrolded cable 500+ devices 500+ ft
WorldFIP Bus Twisted-pair, fiber 256 nodes up to 40 Km
LonWorks


 Bus, ring, loop, star Twisted-pair, fiber, power line 32,000/domain 2000m @ 78 kbps
SDS


 Trunkline/Dropline Twisted-pair for signal & power 64 nodes,
126 addresses		 500m









TRANSPORT MECHANISM

Communication Methods Transmission Properties Data Transfer Size Arbitration Method Error Checking Diagnostics
PROFIBUS DP/PA Master/slave
peer to peer		 DP up to 12 Mbps
PA 31.25 kbps		 244 bytes Token passing HD4 CRC Station, module & channel diagnostics
INTERBUS-S Master/slave with total frame transfer 500kBits/s,
full duplex		 512 bytes h.s.,
unlimited block		 None 16-bit CRC Segment location of CRC error and cable break
DeviceNet Master/slave, multi-master, others 500 kbps,
250 kbps,
125 kbps		 8-byte variable message Carrier-Sonac Multiple Access CRC check Bus monitoring
ARCNET Peer to peer 31.25K to 10M 508 bytes Token 16-bit CRC Built in
AS-I Master/slave with cyclic polling Data and power, EMI resistant 31 slaves with 4 in and 4 out Master/slave with cyclic polling Manchester Code, hamming-2, partly Slave fault, device fault
Fieldbus Foundation Client/server publisher/ subscriber, Event notification 31.25 kbps 1 Mbps 2.5Mbps 16.6 M objects/device Deterministic centralized scheduler, multiple backup 16-bit CRC Remote diagnostics, network monitors, parameter status
IEC/ISA SP50
Fieldbus		 Client/server Publisher/ subscriber 31.25 kbps IS+1, 2.6, 5 Mbps 64 octets high & 256 low priority Scheduler, tokens, or master 16-bit CRC Configurable on network management
Seriplex Master/slave
peer to peer		 200 Mbps 7680/transfer Sonal multiplexing End of frame & echo check Cabling problems
WorldFIP Peer to peer 31.25 kbps, 1 & 2.5 Mbps, 6 Mbps fiber No limit, variables 128 bytes Central arbitration 16-bit CRC, data "freshness" indicator Device message time-out, redundant cabling
LonWorks Master/slave
peer to peer		 1.25 Mbs full duplex 228 bytes Carrier Sense, Multiple Access 16-bit CRC Database of CRC errors and device errors
SDS Master/slave,
peer to peer,
multi-cast,
multi-master		 1Mbps,
500 kbps,
250 kbps,
125 kbps		 8-byte variable message Carrier-Sonac Multiple Access CRC check Bus monitoring,
Diagnostic slave





PERFORMANCE

Cycle Time: 256 Discrete
16 nodes with 16 I/Os		 Cycle Time: 128 Analog
16 nodes with 8 I/Os		 Block transfer of 128 bytes
1 node
PROFIBUS DP/PA Configuration dependent
typ <2ms		 Configuration dependent
typ <2ms		 not available
INTERBUS-S 1.8 ms 7.4 ms 140 ms
DeviceNet 2.0 ms Master-slave polling 10 ms Master-slave polling 4.2 ms
ARCNET <2 ms @ 2.5M <2 ms @ 2.5M <2 ms @ 2.5M
AS-I 4.7 ms not possible not possible
Fieldbus Foundation 100 ms @ 31.25k
<1 ms @ 2.5M		 600 ms @ 31.25k
<8 ms @ 2.5M		 36 ms @ 31.25k
0.45 ms @ 2.5M
IEC/ISA SP50 Configuration dependent Configuration dependent 0.2 ms @ 5 Mbps
1.0 ms @ 1 Mbps
Seriplex 1.32 ms @ 200 kbps, m/s 10.4 ms 10.4 ms
WorldFIP 2 ms @ 1 Mbps 5 ms @ 1 Mbps 5 ms @ 1 Mbps
LonWorks 20 ms 5 ms @ 1 Mbps 5 ms @ 1 Mbps
SDS <1 ms, event driven <1 ms per event 2 ms @ 1 Mbps

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