I/O NETWORK
COMPARISON
BACKGROUND INFORMATION |
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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 |
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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 |
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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 |
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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 |