Specifications

Fieldbus Communications Support
60
31004624 8/2009
The INTERBUS ID Code
Introduction
In the simplest terms, the INTERBUS ID code is a 16-bit word that describes the
data type and data length of network devices.
The ID cycle is part of the INTERBUS network’s initialization process. After
determining the length of its own data during network initialization, every network
device reports its functionality and byte length in the two-byte ID code.
The ID code also includes information about the module type (digital/analog,
input/output/mixed).
The Low and High Bytes
The ID code’s data type is transmitted in the ID code’s low byte, while data length
and message information is reported in the high byte:
1 data type (03h, 33h)
2 data length (0 to 16 words)
3 messages (for management functions)
Data Type
The INTERBUS NIM identifies the device’s data type by recognizing one of two data
types:
NOTE: Data from the HMI panel is analog.
Data Type Signal Direction Signal Type
03h input/output digital
33h input/output analog or mixed