HP 800 HP DTC Cabling and Racking Guide - Page 78

RS-422/RS-423 compatibility, Terminal connections

Get HP 800 PDF manuals and user guides View all HP 800 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 78 highlights

8 A note on standards RS-422/RS-423 compatibility RS-422 and RS-423 are both compatible since they specify the same electrical characteristics for the receiver. However, when connecting devices with different baud rate and distance capabilities, the connection is limited to the baud rate and distance supported by the device with the slower/shorter distance specification. Data In RS-423 Txa Txb RS-422 Rxa Rxb + Data Out Data Out - -Rxa + Rxb Txa Data In Txb Terminal connections Direct terminal connections can be made using either the RS-232, RS-423, or RS422 standards. The table below gives details for each. The distance, data rate, and distance/data rate ratio given here are all maximum values. The conductors column gives the number of conductors necessary for a full-duplex direct connection. Transmission RS-232 Single-ended RS-423 Single-ended RS-422 Differential Conductors Dist 3 50ft 4 4000ft 4 4000ft Data Rate Dist x Data Rate 20 kBaud 100kBaud-ft 100 kBaud 4 MBaud-ft 10 MBaud 400 MBaud-ft 72

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
72
A note on standards
8
RS-422/RS-423 compatibility
RS-422 and RS-423 are both compatible since they specify the same electrical
characteristics for the receiver. However, when connecting devices with different
baud rate and distance capabilities, the connection is limited to the baud rate and
distance supported by the device with the slower/shorter distance specification.
Terminal connections
Direct terminal connections can be made using either the RS-232, RS-423, or RS-
422 standards. The table below gives details for each. The distance, data rate, and
distance/data rate ratio given here are all maximum values. The conductors column
gives the number of conductors necessary for a full-duplex direct connection.
Data
In
Data
Out
RS-423
-
+
RS-422
Txa
Txb
Rxa
Rxb
Data
In
Data
Out
-
Txa
Txb
Rxa
Rxb
-
+
Transmission
Conductors
Dist
Data Rate
Dist x Data
Rate
RS-232
Single-ended
3
50ft
20 kBaud
100kBaud-ft
RS-423
Single-ended
4
4000ft
100 kBaud
4 MBaud-ft
RS-422
Differential
4
4000ft
10 MBaud
400 MBaud-ft