Specifications

Fieldbus Communications Support

31004624 8/2009

Node Error (Selector 35h–44h)

Node error is an array of 8 words. Each bit represents one specific addressable I/O

module on the island bus. After the master receives an emergency message (not

error-free) from a module, the corresponding bit is set:

z A value of 1 in a bit position indicates the presence of a newly received

emergency message.

z A value of 0 in a bit position indicates that no values have changed since the last

reading of the diagnostic buffer.

When the selector value is from 35h to 44h, information about a particular module’s

error message (according to the following table) is transmitted as the status word’s

low byte value:

The INTERBUS NIM supports a maximum of 32 modules. The first four bytes (35h–

38h) provide the 32 bits that represent the module locations in a typical island

configuration. The remaining diagnostic bytes are available to support island

expansion capabilities.

Device Information (Selector 45h)

When the selector value is 45h, device information is transmitted as the status

word’s low byte value according to the meaning of bits in the following table:

Selector Value Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Status Data

35h 87654321modules 1–8

36h 16 15 14 13 12 11 10 9 modules 9–16

37h 24 23 22 21 20 19 18 17 modules 17–24

38h 32 31 30 29 28 27 26 25 modules 25–32

. . .

43h 120 119 118 117 116 115 114 113 modules 113–120

44h 127 126 125 124 123 122 121 modules 121–127

Bit Meaning

D0/D1 The combined value of 2 for these two bits indicates the standard version of the

INTERBUS NIM (STB NIB 2212).

The combined value of 3 for these two bits indicates the premium version of the

INTERBUS NIM.

D2* input word limit—When set (bit value = 1), the input word length exceeds the 16-

word limit. When not set (bit value = 0), the input word length is within the 16-word

limit.

D3* output word limit—When set (bit value = 1), the output word length exceeds the 16-

word limit. When not set (bit value = 0), the output word length is within the 16-word

limit, or bit D2 is already set.