MS/TP Bus cable recommendations - Metasys - LIT-12011034 - General System Information - Metasys System - Release 11.0

MS/TP Communications Bus Technical Bulletin

Brand
Metasys
Product name
Metasys System
Document type
Technical Bulletin
Document number
LIT-12011034
Version
Release 11.0
Revision date
2022-02-07
Language
English

The MS/TP bus supports much higher baud rates than the N2 bus. Higher baud rates make the MS/TP bus less fault tolerant and less immune to interference from inductive noise sources that may be present in the application environment.

For the best performance on MS/TP bus applications, use 22 AWG stranded wire in a shielded cable with proper cable shield grounding. This recommendation applies to both local and Remote Field Bus installations. Other wire gauges and non-shielded cable may provide acceptable bus performance in many applications, especially applications that have short cable runs and low ambient inductive noise levels.

Table 1 provides cable recommendations for MS/TP applications. The recommended FC bus and SA bus cables are available from Belden CDT Inc. and Anixter, Inc.

Alternative cables may be used in MS/TP applications. Table 2 provides information regarding the relationship between baud rate, wire gauge, wire length, and supported device numbers. You can also use the information provided in Table 2 to determine if existing cable runs may be used in a retrofit or upgrade MS/TP application.

Note: In Table 1, the shielded bus and cable types are recommended; the non-shielded bus and cable types are acceptable.
Table 1. Cable for FC Buses and SA Buses in order of preference

Bus and cable type

Non-plenum applications

Plenum applications

Part number

O.D.

Part number

O.D.

FC Bus: 22 AWG Stranded, 3-Wire Twisted Shielded Cable

Anixter: CBL-22/3-FC-PVC

Belden®: B5501FE

0.138 in.

Anixter: CBL-22/3-FC-PLN

Belden: B6501FE

0.140 in.

SA Bus (terminal block): 22 AWG Stranded, 4-Wire, 2 Twisted-Pair Shielded Cable

Anixter: CBL-22/2P-SA-PVC

Belden: B5541FE

0.209 in.

Anixter: CBL-22/2P-SA-PLN

Belden: B6541FE

0.206 in.

SA Bus (modular jack): 26 AWG Solid 6-Wire, 3 Twisted-Pair Cable

Anixter preassembled:

CBL-NETWORK25

CBL-NETWORK50

CBL-NETWORK75

CBL-NETWORK100

0.15 in.

FC Bus: 22 AWG Stranded, 3-Wire Twisted Non-Shielded Cable

Belden: B5501UE

0.135 in.

Belden: B6501UE

0.131 in.

SA Bus (terminal block): 22 AWG Stranded, 4-Wire, 2 Twisted-Pair Non-Shielded Cable

Belden: B5541UE

0.206 in.

Belden: B6541UE

0.199 in.

Note: We strongly recommend 3-wire (for FC bus) and 4-wire, 2 twisted-pair (for SA bus), 22 AWG stranded, shielded cable. A 22 gauge cable offers the best performance for various baud rates, cable distances, and number of trunk devices primarily due to lower conductor-to-conductor capacitance. Shielded cable offers better overall electrical noise immunity than non-shielded cable. Observe the shield grounding requirements.
Note: We recommend 26 AWG solid, 6-wire (3 twisted pairs) cable as the best fit for fabricating modular cables with the modular jack housing assembly. Be sure the cable you use fits the modular jack housing. The preassembled cables that are available from Anixter (Part No. CBL-NETWORKxxx) use 24 gauge wire.

Table 2. FC Bus wire gauge and FC Bus baud rate

AWG wire gauge

Maximum cable length and device connections limit

Baud rate

9600

19,200

38,400

76,800

18

Maximum cable length per Bus segment (m [ft])

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

1,219 (4,000)

(NR)

609 (2,000)

(NR)

305 (1,000)

(NR)

Maximum number of devices (per segment / per FC Bus)

25/25

(APR)

50/50

(APR)

50/100

(NR)

10/30

(NR)

50/100

(NR)

20

Maximum cable length per Bus segment (m [ft])

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

1,524 (5,000)

(NR)

1,219 (4,000)

(NR)

Maximum number of devices (per segment / per FC Bus)

25/25

(APR)

50/50

(APR)

50/100

(APR)

40/100

(NR)

50/100

(NR)

22

Maximum cable length per Bus segment (m [ft])

1,524 (5,000)

(A)

1,524 (5,000)

(A)

1,524 (5,000)

(Best)

1,524 (5,000)

(A)

Maximum number of devices (per segment / per FC Bus)

25/25

(A)

50/50

(A)

50/100

(Best)

50/100

(A)

24

Maximum cable length per Bus segment (m [ft])

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

Maximum number of devices (per segment / per FC Bus)

25/25

(APR)

50/50

(APR)

50/100

(APR)

50/100

(APR)

26

Maximum cable length per Bus segment (m [ft])

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

1,524 (5,000)

(APR)

Maximum number of devices (per segment / per FC Bus)

25/25

(APR)

50/50

(APR)

50/100

(APR)

50/100

(APR)

A = Acceptable

APR = Acceptable with Possible Restrictions

NR = Not Recommended

   
Note: The maximum number of devices is reduced at lower baud rates (9,600, 19,200) due to increased token loop times.
Note: 3-wire conductor (FC Bus), 22 AWG stranded, shielded cable is recommended. 22 gauge cable offers the best performance for various baud rates, cable distances, and number of trunk devices primarily due to lower conductor-to-conductor capacitance. Shielded cable offers better overall electrical noise immunity than non-shielded cable.
Note: The MS-NAE55xx-0 cannot communicate at 76,800 baud.